and have no fellowship with the unfruitful works of the darkness and rather even convict,

Have nothing to do with the barren unprofitable deeds of darkness, but, instead of that, set your faces against them;

And have no company with the works of the dark, which give no fruit, but make their true quality clear;

And so, have no fellowship with the unfruitful works of darkness, but instead, refute them.

Take no part in deeds of darkness, from which no good can come; on the contrary, expose them.

Et ne communicetis operibus infructuosis tenebrarum; quin potius etiam redarguitote.

And have no fellowship. As "the children of light" dwell amidst the darkness, or, in other words, in the midst of "a perverse and crooked generation," (Deuteronomy 32:5,) -- there is good reason for warning them to keep themselves apart from wicked actions. It is not enough that we do not, of our own accord, undertake anything wicked. We must beware of joining or assisting those who do wrong. In short, we must abstain from giving any consent, or advice, or approbation, or assistance; for in all these ways we have fellowship. And lest any one should imagine that he has done his duty, merely by not conniving, he adds, but rather reprove them. [1] Such a course is opposed to all dissimulation. Where a manifest offense is committed against God, every man will be eager to vindicate himself from any share in the guilt, but very few will guard against connivance; nearly all will practice some kind of dissimulation. But rather than the truth of God shall not remain unshaken, let a hundred worlds perish. The word elenchein, which is translated reprove, answers to the metaphor of darkness; for it literally signifies to drag forth to the light what was formerly unknown. As ungodly men flatter themselves in their vices, (Psalm 36:2,) and wish their crimes to be concealed, or to be reckoned virtues, Paul enjoins that they shall be reproved. He calls them unfruitful; because they not only do no good, but are absolutely hurtful.

Footnotes

1 - "Most expositors supply autous, meaning the doers of the works; and they render elenchete, reprove, viz., by wholesome correction. This, however, is so harsh, that it is better (with Theodoret, the Pesch. Syr., Wakefield, Schleusner, Photius, and Wahl) to supply auta, that is, erga tou skotous, and to interpret elenchete bring to the light, and evince their evil nature,' namely, by shewing in contrast the opposite virtues. This sense is required by verse 13, with which the present closely connects; and so elencho is used both in the Scriptural and Classical writers." -- Bloomfield.

And have no fellowship - See the sentiment here expressed fully explained in the notes on 2-Corinthians 6:14-18.
The unfruitful works - The deeds of darkness that produce no "benefit" to the body or the soul. The word "unfruitful" is used here in contrast with the "fruit of the Spirit," Ephesians 5:9.
But rather reprove them - By your life, your conversation, and all your influence. This is the business of Christians. Their lives should be a standing rebuke of a sinful world, and they should be ever ready to express their disapprobation of its wickedness in every form.

Have no fellowship - Have no religious connection whatever with heathens or their worship.
Unfruitful works of darkness - Probably alluding to the mysteries among the heathens, and the different lustrations and rites through which the initiated went in the caves and dark recesses where these mysteries were celebrated; all which he denominates works of darkness, because they were destitute of true wisdom; and unfruitful works, because they were of no use to mankind; the initiated being obliged, on pain of death, to keep secret what they had seen, heard, and done: hence they were called απορῥητα μυστηρια, unspeakable mysteries - things that were not to be divulged. That the apostle may refer to magic and incantations is also probable, for to these the Ephesians were greatly addicted. See the proofs in the notes on Acts 19:19.
Rather reprove them - Bear a testimony against them; convince them that they are wrong; confute them in their vain reasons; reprove them for their vices, which are flagrant, while pretending to superior illumination. All these meanings has the Greek word ελεγχω, which we generally render to convince or reprove.

And have no fellowship with the unfruitful works of darkness, but rather (e) reprove [them].
(e) Make them open to all the world, by your good life.

And have no fellowship with the unfruitful works of darkness,.... It is not said with the workers of darkness, or with the men of the world, who are in darkness, and are darkness itself; to have fellowship with them in a civil way, or to dwell among them, is not prohibited; it is allowed of, and countenanced by the greatest examples; and especially it is lawful and right, when there is any prospect of doing good to the souls of men; and even when natural right, relation, and necessity require it; and indeed, the contrary is impracticable: conversation with them in things sinful and superstitious should be abstained from; and when it tends to draw off the soul from Christ and his interest, and is infectious; and when weak ones are offended, and sinners are hereby hardened and confirmed in sin; and the name of God is blasphemed, and the Gospel is evil spoken of: but fellowship is not to be maintained "with the works of darkness"; which are sins, so called, because they are opposite to light; to the light of nature, to the light of the divine word, both law and Gospel, to the light of grace, to God the fountain of light, and to Christ the light of the world; and because the source and spring of them are the original darkness of the mind, and Satan the prince of darkness; and because they are generally committed in the dark; and because the effect and consequence of them is utter darkness, and blackness of darkness: and these are "unfruitful"; they are of no profit and advantage, they bring forth no fruit, unless it be guilt, fear, shame, corruption, and death; wherefore no fellowship should be had with them, by committing the same, by assisting in them, by consenting to them, by approving of them, by receiving any worldly advantage from them, and by winking and conniving at them: it is contrary to the character of saints to have fellowship with such, as the apostle says, 2-Corinthians 6:14, where he gives the mystical explanation of the law, in Deuteronomy 22:10; agreeably to which, and to the passage here, is the sense of a Jewish commentators (l) who upon it observes, that that law
"intimates that a righteous man, , "should have no fellowship" with a wicked man;''
this is to be unequally yoked, signified by the ox and the ass ploughing together:
but rather reprove them; both by words and by deeds, by an agreeable life and conversation, which last seems to be the design of the apostle here; because it is not a brother, but such who are in darkness, and live in works of darkness; yea, not sinners, but sins are to be reproved, which can be done no other way; nor are all saints proper to reprove verbally, nor are they qualified for it; but all should, and may by facts; and the light discovers darkness, by its own splendour; and this appears from the apostle's reasoning in the next words.
(l) Baal Hatturira in Deut. xxii. 10.

unfruitful works of darkness--Sins are terminated in themselves, and therefore are called "works," not "fruits" (Galatians 5:19, Galatians 5:22). Their only fruit is that which is not in a true sense fruit (Deuteronomy 32:32), namely, "death" (Romans 6:21; Galatians 6:8). Plants cannot bear "fruit" in the absence of light. Sin is "darkness," and its parent is the prince of darkness (Ephesians 6:12). Graces, on the other hand, as flourishing in "the light," are reproductive, and abound in fruits; which, as harmoniously combining in one whole, are termed (in the singular) "the FRUIT of the Spirit" (Ephesians 5:9).
rather, &c.--Translate as Greek, "rather even reprove them" (compare Matthew 5:14-16). Not only "have no fellowship, but even reprove them," namely, in words, and in your deeds, which, shining with "the light," virtually reprove all that is contrary to light (Ephesians 5:13; John 3:19-21). "Have no fellowship," does not imply that we can avoid all intercourse (1-Corinthians 5:10), but "avoid such fellowship as will defile yourselves"; just as light, though it touch filth, is not soiled by it; nay, as light detects it, so, "even reprove sin."

And have no fellowship. See Ephesians 5:7. Works of darkness are those which please the powers of darkness. The Christian must have nothing whatever to do with these. We must not countenance any sinful device, but rather reprove it. This would prevent the patronage of many things which the world countenances.
For the things which are done by them in secret. In the works of darkness are many secret sins, some too shameful even to be named.
But all things that are reproved. These works of darkness are to be reproved by Christians (Ephesians 5:11) that their true character may be brought to light. If the light is thrown upon them they will be seen.
Everything that is made manifest is light. Whatever is brought to light is light. Even if wicked, when it is brought to light it enlightens men by revealing its real nature.
Wherefore he saith. Who says, or where, is uncertain. There is a similar thought in Isaiah 60:1-2 and Isaiah 26:19. He probably means that God, in substance, says.
Awake, thou that sleepest. The sleeper represents one not converted.
Arise from the dead. From death in sin (Ephesians 2:1). Conversion is often described as a spiritual resurrection (Romans 6:4-6; Colossians 2:12).
And Christ. Christ gives light to all who come to him. The Greek quotation is in verse, and has been translated,

Reprove them - To avoid them is not enough.