JLB 2 Tim 2:13 if we are faithless, he remains faithful, for he cannot disown himself.
Matthew Henry's Concise Commentary
http://biblehub.com/2_timothy/2-13.htm
2:8-13 Let suffering saints remember, and look to Jesus, the Author and Finisher of their faith, who for the joy that was set before him, endured the cross, despised the shame, and is now set down at the right hand of the throne of God. We must not think it strange if the best men meet with the worst treatment; but this is cheering, that the word of God is not bound. Here we see the real and true cause of the apostle's suffering trouble in, or for, the sake of the gospel. If we are dead to this world, its pleasures, profits, and honours, we shall be for ever with Christ in a better world. He is faithful to his threatenings, and faithful to his promises.
This truth makes sure the unbeliever's condemnation, and the believer's salvation.
Gill's Exposition of the Entire Bible
http://biblehub.com/2_timothy/2-13.htm
If we believe not, yet he abideth faithful,.... The Syriac and Ethiopic versions read, "if we believe not him". This may be understood, either of such who are altogether destitute of faith, who do not believe in Christ at all; and particularly do not believe what was just now said concerning his denying such that deny him, but mock and scoff at his coming, and at a future judgment: this unbelief of theirs will not make void his faith or faithfulness; see Romans 3:3, he will abide faithful to his word of threatening; and what he says in Mark 16:16 will be found to be an everlasting truth:
or it may be understood of true believers, whose faith sometimes is very low, as to its exercise on Christ, and with reference to their future glory and happiness; but Christ is faithful to all his, covenant engagements for them, to bring them to glory, and to every word of promise concerning their happiness, and to every branch of the faithful saying above mentioned; and he is ever the same in his love to them, and in the efficacy of his blood, righteousness, and sacrifice;
and his salvation is an everlasting and unchangeable one; nor do the saints' interest in it, and security by it, depend upon their acts of believing, or their frames, but upon the firmness and unchangeableness of Christ, the object of faith.
He cannot deny himself; he cannot go contrary to his word; that would be to act contrary to his nature and perfections, and would be a denying of himself, which is not possible; wherefore his faithfulness will never fail, even though, the faith of his people does, as to the exercise of it.
Jamieson-Fausset-Brown Bible Commentary
http://biblehub.com/2_timothy/2-13.htm
13. believe not—"If we are unbelievers (literally, 'unfaithful'), He remains faithful" (De 7:9, 10). The oldest manuscripts read, "For He cannot (it is an impossibility that He should) deny Himself." He cannot be unfaithful to His word that He will deny those who deny Him, though we be not faithful to our profession of faith in Him (Ro 3:3). Three things are impossible to God, to die, to lie, and to be deceived [Augustine, The Creed, 1.1], (Heb 6:18). This impossibility is not one of infirmity, but of infinite power and majesty.
Also, indirectly, comfort is suggested to believers, that He is faithful to His promises to them; at the same time that
apostates are shaken out of their self-deceiving fancy, that because they change, Christ similarly may change. A warning to Timothy to be steadfast in the faith.
