I reckon not myself to have as yet apprehended He does not here call in question the certainty of his salvation, as though he were still in suspense, but repeats what he had said before -- that he still aimed at making farther progress, because he had not yet attained the end of his calling. He shews this immediately after, by saying that he was intent on this one thing, leaving off everything else. Now, he compares our life to a race-course, the limits of which God has marked out to us for running in. For as it would profit the runner nothing to have left the starting-point, unless he went forward to the goal, so we must also pursue the course of our calling until death, and must not cease until we have obtained what we seek. Farther, as the way is marked out to the runner, that he may not fatigue himself to no purpose by wandering in this direction or in that, so there is also a goal set before us, towards which we ought to direct our course undeviatingly; and God does not permit us to wander about heedlessly. Thirdly, as the runner requires to be free from entanglement, and not stop his course on account of any impediment, but must continue his course, surmounting every obstacle, so we must take heed that we do not apply our mind or heart to anything that may divert the attention, but must, on the contrary, make it our endeavor, that, free from every distraction, we may apply the whole bent of our mind exclusively to God's calling. These three things Paul comprehends in one similitude. When he says that he does this one thing, and forgets all things that are behind, he intimates his assiduity, and excludes everything fitted to distract. When he says that he presses toward the mark, he intimates that he is not wandering from the way. Forgetting those things that are behind He alludes to runners, who do not turn their eyes aside in any direction, lest they should slacken the speed of their course, and, more especially, do not look behind to see how much ground they have gone over, but hasten forward unremittingly towards the goal, Thus Paul teaches us, that he does not think of what he has been, or of what he has done, but simply presses forward towards the appointed goal, and that, too, with such ardor, that he runs forward to it, as it were, with outstretched arms. For a metaphor of this nature is implied in the participle which he employs. [1] Should any one remark, by way of objection, that the remembrance of our past life is of use for stirring us up, both because the favors that have been already conferred upon us give us encouragement to entertain hope, and because we are admonished by our sins to amend our course of life, I answer, that thoughts of this nature do not turn away our view from what is before us to what is behind, but rather help our vision, so that we discern more distinctly the goal. Paul, however, condemns here such looking back, as either destroys or impairs alacrity. Thus, for example, should any one persuade himself that he has made sufficiently great progress, reckoning that he has done enough, he will become indolent, and feel inclined to deliver up the lamp [2] to others; or, if any one looks back with a feeling of regret for the situation that he has abandoned, he cannot apply the whole bent of his mind to what he is engaged in. Such was the nature of the thoughts from which Paul's mind required to be turned away, if he would in good earnest follow out Christ's calling. As, however, there has been mention made here of endeavor, aim, course, perseverance, lest any one should imagine that salvation consists in these things, or should even ascribe to human industry what comes from another quarter, with the view of pointing out the cause of all these things, he adds -- in Christ Jesus

Footnotes

1 - The participle referred to is epekteinomenos, which, as is remarked by Dr. Bloomfield, "is highly appropriate to the racer, whether on foot, or on horseback, or in the chariot; since the racer stretches his head and hands forward in anxiety to reach the goal." -- Ed.

2 - A proverbial expression, founded on the circumstance that in certain games at Athens the runners had to carry a lamp, or burning torch, in such a way that it should not go out, and, on any one of the competitors giving up the contest, he delivered up the lamp, or torch, to his successor, See Auct. ad Herenn. 1. 4, c. 46; Lucret. I. 2, 5:77 -- Ed.

Brethren, I count not myself to have apprehended - That is, to have obtained that for which I have been called into the service of the Redeemer. There is something which I strive after which I have not yet gained. This statement is a confirmation of the opinion that in the previous verse, where he says that he was not "already perfect," he includes a moral perfection, and not merely the obtainment of the prize or reward; for no one could suppose that he meant to be understood as saying that he had obtained the crown of glory.
This one thing I do - Paul had one great aim and purpose of life. He did not attempt to mingle the world and religion, and to gain both. He did not seek to obtain wealth and salvation too; or honor here and the crown of glory hereafter, but he had one object, one aim, one great purpose of soul. To this singleness of purpose he owed his extraordinary attainments in piety, and his uncommon success as a minister. A man will accomplish little who allows his mind to be distracted by a multiplicity of objects. A Christian will accomplish nothing who has not a single great aim and purpose of soul. That purpose should be to secure the prize, and to renounce everything that would be in the way to its attainment. Let us then so live that we may be able to say, that there is one great object which we always have in view, and that we mean to avoid everything which would interfere with that.
Forgetting those things which are behind - There is an allusion here undoubtedly to the Grecian races. One running to secure the prize would not stop to look behind him to see how much ground he had run over, or who of his competitors had fallen or lingered in the way. He would keep his eye steadily on the prize, and strain every nerve that he might obtain it. If his attention was diverted for a moment from that, it would hinder his flight, and might be the means of his losing the crown. So the apostle says it was with him. He looked onward to the prize. He fixed the eye intently on that. It was the single object in his view, and he did not allow his mind to be diverted from that by anything - not even by the contemplation of the past. He did not stop to think of the difficulties which he had overcome, or the troubles which he had met, but he thought of what was yet to be accomplished.
This does not mean that he would not have regarded a proper contemplation of the past life as useful and profitable for a Christian (compare the notes at Ephesians 2:11), but that he would not allow any reference to the past to interfere with the one great effort to win the prize. It may be, and is, profitable for a Christian to look over the past mercies of God to his soul, in order to awaken emotions of gratitude in the heart, and to think of his shortcomings and errors, to produce penitence and humility. But none of these things should be allowed for one moment to divert the mind from the purpose to win the incorruptible crown. And it may be remarked in general, that a Christian will make more rapid advances in piety by looking forward than by looking backward. Forward we see everything to cheer and animate us - the crown of victory, the joys of heaven, the society of the blessed - the Saviour beckoning to us and encouraging us.
Backward, we see everything to dishearten and to humble. Our own unfaithfulness; our coldness, deadness, and dullness; the little zeal and ardor which we have, all are fitted to humble and discourage. He is the most cheerful Christian who looks onward, and who keeps heaven always in view; he who is accustomed much to dwell on the past, though he may be a true Christian, will be likely to be melancholy and dispirited, to be a recluse rather than a warm-hearted and active friend of the Saviour. Or if he looks backward to contemplate what he has done - the space that he has run over - the difficulties which he has surmounted - and his own rapidity in the race, he will be likely to become self-complacent and self-satisfied. He will trust his past endeavors, and feel that the prize is now secure, and will relax his future efforts. Let us then look onward. Let us not spend our time either in pondering the gloomy past, and our own unfaithfulness, or in thinking of what we have done, and thus becoming puffed up with self-complacency; but let us keep the eye steadily on the prize, and run the race as though we had just commenced it.
And reaching forth - As one does in a race.
Unto those things which are before - Before the racer there was a crown or garland to be bestowed by the judges of the games. Before the Christian there is a crown of glory, the eternal reward of heaven. There is the favor of God, victory over sin and death, the society of the redeemed and of angelic beings, and the assurance of perfect and eternal freedom from all evil. These are enough to animate the soul, and to urge it on with ever-increasing vigor in the christian race.

I count not myself to have apprehended - Whatever gifts, graces, or honors I may have received from Jesus Christ, I consider every thing as incomplete till I have finished my course, got this crown, and have my body raised and fashioned after his glorious body.
This one thing I do - This is the concern, as it is the sole business, of my life.
Forgetting those things which are behind - My conduct is not regulated nor influenced by that of others; I consider my calling, my Master, my work, and my end. If others think they have time to loiter or trifle, I have none: time is flying; eternity is at hand; and my all is at stake.
Reaching forth - The Greek word επεκτεινομενος points out the strong exertions made in the race; every muscle and nerve is exerted, and he puts forth every particle of his strength in running. He was running for life, and running for his life.

Brethren, I count not myself to have apprehended,.... That for which he was apprehended of Christ: he had not attained to perfect knowledge, was not come to the mark, had not received the prize, or laid hold on eternal life; though he had received so much grace, and such gifts, as had qualified him for an apostle; and he had been so many years in that office, and had so great a knowledge in the mystery of the Gospel, and had laboured in it more abundantly than others, and with great success; and even though he had been caught up into the third heaven, and had heard unspeakable words, not lawful to be uttered, 2-Corinthians 12:2, yet he had no such opinion of himself, as if he was perfect: by which way of speaking, he tacitly strikes at the arrogance and vain confidence of false teachers, that pretended to perfection; and in this way led the brethren to conclude, that they could never have arrived to it, since so great an apostle had not; some copies read not "yet", and so the Ethiopic version:
but this one thing I do; which he was intent upon, constantly attended to, and earnestly pursued; it was the main and principal thing he was set upon, and which he employed himself in; and which engrossed all his thoughts, desires, affections, time, and labour; see Psalm 27:4. The Syriac version reads, "this one thing I know"; signifying that whatever he was ignorant of, and however imperfect his knowledge was in other things, this he was full well apprized of, and acquainted with. The Arabic version renders the whole thus, "I do not think that I have now obtained and received anything, but the one thing"; namely, what follows,
forgetting those things which are behind, meaning not the sins of his past life, which were indeed forgotten by God, and the guilt of which was removed from him, by the application of the blood of Christ, so that he had no more conscience of them; yet they were remembered and made mention of by him, partly for his own humiliation, and partly to magnify the grace of God: nor earthly and worldly things, which believers are too apt to have respect to, to look back upon, and hanker after, as the Israelites did after the fleshpots in Egypt, Exodus 16:3; though these were forgotten by the apostle, so as not anxiously to care for them, and seek after them, to set his affections on them, or trust in them: nor his fleshly privileges, and legal righteousness, which he pursued, valued, and trusted in before conversion, but now dropped, renounced, disregarded, and counted as loss and dung, Philippians 3:7; but rather his labours and works of righteousness since conversion, which though he times took notice of for the magnifying of the grace of God, for the defence of the Gospel, and to put a stop to the vain boasting of false teachers, yet he forgot them in point of dependence on them, and trust to them; and having put his hand to the plough, he did not look back, nor desist, but went on in his laborious way, not thinking of what he had done and gone through, nor discouraged at what was before him; as also he intends all his growth in grace, and proficiency in divine knowledge, which was very, great; and though he was thankful for these things, and would observe them to the glory of the grace of God, yet he trusted not in them: nor did he sit down easy and satisfied with what he had attained unto, and therefore was
reaching forth unto those things which are before; to perfection of knowledge, holiness, and happiness, which were before him, and he as yet had not attained unto; but was desirous of, and pursued after with great vehemence and eagerness; the metaphor is taken from runners in a race, who did not stop to look behind them, and see what way they have run, and how far they are before others, but look and move forwards, and stretch themselves out to the uttermost, and run with all their might and main to the mark before them; and so the apostle did in a spiritual sense.

I--whatever others count as to themselves. He who counts himself perfect, must deceive himself by calling sin infirmity (1-John 1:8); at the same time, each must aim at perfection, to be a Christian at all (Matthew 5:48).
forgetting those things . . . behind--Looking back is sure to end in going back (Luke 9:62): So Lot's wife (Luke 17:32). If in stemming a current we cease pulling the oar against it, we are carried back. God's word to us is as it was to Israel, "Speak unto the children of Israel that they go forward" (Exodus 14:15). The Bible is our landmark to show us whether we are progressing or retrograding.
reaching forth--with hand and foot, like a runner in a race, and the body bent forward. The Christian is always humbled by the contrast between what he is and what he desires to be. The eye reaches before and draws on the hand, the hand reaches before and draws on the foot [BENGEL].
unto--towards (Hebrews 6:1).

I do not account myself to have apprehended this already; to be already possessed of perfect holiness.