Be strong in the grace As he had formerly commanded him to keep, by the Spirit, that which was committed to him, so now he likewise enjoins him "to be strengthened in grace." By this expression he intends to shake off sloth and indifference; for the flesh is so sluggish, that even those who are endued with eminent gifts are found to slacken in the midst of their course, if they be not frequently aroused. Some will say: "Of what use is it to exhort a man to be strong in grace,' unless free-will have something to do in cooperation?" I reply, what God demands from us by his word he likewise bestows by his Spirit, so that we are strengthened in the grace which he has given to us. And yet the exhortations are not superfluous, because the Spirit of God, teaching us inwardly, causes that they shall not sound in our ears fruitlessly and to no purpose. Whoever, therefore, shall acknowledge that the present exhortation could not have been fruitful without the secret power of the Spirit, will never support free-will by means of it. Which is in Christ Jesus. This is added for two reasons; to shew that the grace comes from Christ alone, and from no other, and that no Christian will be destitute of it; for, since there is one Christ common to all, it follows that all are partakers of his grace, which is said to be in Christ, because all who belong to Christ must have it. My son. This kind appellation, which he employs, tends much to gain the affections, that the doctrine may more effectually obtain admission into the heart.

Thou therefore - In view of the fact stated in the previous chapter, that many had turned away from the apostle, and had forsaken the paths of truth.
Be strong in the grace which is in Christ Jesus; - compare the notes at Ephesians 6:10. The meaning is, Be strong, relying on the grace which the Lord Jesus only can impart.

Be strong in the grace - Though the genuine import of the word grace is favor, yet it often implies an active principle communicated from God; light directing how to act, and power enabling to act according to the light.

Thou (1) therefore, my son, be strong in the grace that is in Christ Jesus.
(1) The conclusion of the former exhortation which has also a declaration added to it: how those who do not keep that worthy thing that is committed to them, who keep it to themselves, but rather those who do most freely communicate it with others, to the end that many may be partakers of it, without any man's loss or hindrance.

Thou therefore, my son,.... The illative particle, "therefore", shows the connection between this and the preceding chapter; the appellation, "thou, my son", expresses the apostle's tender affection for Timothy, and is the rather used to engage his attention to the advice he was about to give him; which is, that since he had received the true grace of God, and unfeigned faith dwelt in him; and since he had such gifts, qualifying him for the work of the ministry; and since so good a thing as the glorious Gospel of the blessed God was committed to his trust; and since there were so many who had departed from it, and so few that abode by it, he would have him
be strong in the grace that is in Christ Jesus; by which may be meant either the free favour and love of God in Christ, Romans 8:39 which is in itself always strong, immovable, and unalterable; and is the strength and security of the saints, though they have not always the same strong believing views of it; and to be strong in it, is to be rooted and grounded in it, and to have a strong sense and firm persuasion of interest in it, and that nothing can separate from it: or else the Gospel, which is a declaration of grace, and is in Christ, and comes by him; and to be strong in it, is to preach it boldly, to defend it bravely, and courageously oppose every error and heresy, and every abettor thereof; and it also becomes every private believer to hold it fast, stand fast in it, abide by it, and earnestly contend for it; and so the phrase may stand opposed to , or "one strong in the law", which is so often used by the Jews (d): or rather by grace is meant the fulness of grace which is in Christ, for the supply of his people; for in that grace which is in him, and not in that which is in themselves, should their dependence be. It is very agreeable to be strong in grace received, in point of exercise, but not in point of contentment; so as to rest satisfied with the present measure of it, without growing in it, and going on to perfection; and much less in point of consolation, so as to derive peace and comfort from it; and still less in point of trust and confidence in it; for it is but a creature, though a very glorious one, being the workmanship of God, and very variable as to its exercise, and as yet imperfect; and not that, but the object of it, is to be trusted in: though indeed a person's enjoyment of everlasting glory and happiness may be strongly concluded from the work of grace which is begun in him; that being an immortal seed, and a well of living water springing up into eternal life; and with which glory is inseparably connected. But grace in Christ is what believers should always have recourse unto, and exercise faith on; and not only believe that there is such a fulness of grace in Christ, which they have both heard of and seen, and which they know is laid up for them, and given to them, and is sufficient for them; but they should go forth out of themselves unto it, and draw water with joy out of the full wells of salvation in Christ: and this grace is of a strengthening nature, both to ministers of the word, to enable them to fulfil their ministry, to bear reproaches, afflictions, and persecution for the Gospel, and the infirmities of weak brethren; and to private believers, to strengthen them against every corruption, temptation, and snare, to exercise every grace, and discharge every branch of duty.
(d) Targum in Ruth ii. 1. & in Psal. lxxxii. 1. & cxii. 2. & in Eccl. x. 17. & in Cant. viii. 10, vid. T. Bab. Sota, fol. 14. 1. & Tzeror Hammor, fol. 9. 3.

As our trials increase, we need to grow stronger in that which is good; our faith stronger, our resolution stronger, our love to God and Christ stronger. This is opposed to our being strong in our own strength. All Christians, but especially ministers, must be faithful to their Captain, and resolute in his cause. The great care of a Christian must be to please Christ. We are to strive to get the mastery of our lusts and corruptions, but we cannot expect the prize unless we observe the laws. We must take care that we do good in a right manner, that our good may not be spoken evil of. Some who are active, spend their zeal about outward forms and doubtful disputations. But those who strive lawfully shall be crowned at last. If we would partake the fruits, we must labour; if we would gain the prize, we must run the race. We must do the will of God, before we receive the promises, for which reason we have need of patience. Together with our prayers for others, that the Lord would give them understanding in all things, we must exhort and stir them up to consider what they hear or read.

EXHORTATIONS; TO FAITHFULNESS AS A GOOD SOLDIER OF CHRIST; ERRORS TO BE SHUNNED; THE LORD'S SURE FOUNDATION; THE RIGHT SPIRIT FOR A SERVANT OF CHRIST. (2Ti. 2:1-26)
Thou therefore--following my example (2-Timothy 1:8, 2-Timothy 1:12), and that of ONESIPHORUS (2-Timothy 1:16-18), and shunning that of those who forsook me (2-Timothy 1:15).
my son--Children ought to imitate their father.
be strong--literally, "be invested with power." Have power, and show thyself to have it; implying an abiding state of power.
in the grace--the element IN which the believer's strength has place. Compare 2-Timothy 1:7, "God hath given us the spirit of power."

Thou, therefore, my son. Since his son, Timothy, should follow his example, and seek to be strong through the grace of Christ.
And the things that thou hast heard of me. The instruction that I gave thee to fit thee for preaching Christ, do thou impart to other men, faithful, in order that they may be able to teach others also. As Paul prepared Timothy to preach the gospel, so he is to prepare other men.
Among many witnesses. This probably refers to Timothy hearing Paul teach these things before many congregations.
Faithful men. Trustworthy men.