1-corinthians 1:8

Who shall - confirm you - As the testimony of Christ was confirmed among you, so, in conscientiously believing and obeying, God will confirm you through that testimony. See 1 Corinthians 1:6.

In the day of our Lord Jesus - In the day that he comes to judge the world, according to some; but, in the day in which he comes to destroy the Jewish polity, according to others. While God destroys them who are disobedient, he can save you who believe.

Who shall also confirm you - Who shall establish you in the hopes of the gospel. He shall make you "firm" (βεβαιώσει bebaiōsei) amidst all your trials, and all the efforts which may be made to shake your faith, and to remove you from that firm foundation on which you now rest.

Unto the end - That is, to the coming of the Lord Jesus Christ. He would keep them to the end of life in the path of holiness, so that at the coming of the Lord Jesus they might be found blameless; compare John 13:1. The sense is, that they should be kept, and should not be suffered to fall away and perish - and this is one of the many places which express the strong confidence of Paul that those who are true Christians shall be preserved unto everlasting life; compare Philippians 1:6.

That ye may be blameless - The word rendered "blameless" ἀνεγκλήτου anegklētou does not mean perfect, but properly denotes those against whom there is no charge of crime; who are unaccused, and against whom there is no ground of accusation. Here it does not mean that they were personally perfect, but that God would so keep them, and enable them to evince a Christian character, as to give evidence that they were his friends, and completely escape condemnation in the last Day; see the notes at Romans 8:33-34. There is no man who has not his faults; no Christian who is not conscious of imperfection; but it is the design of God so to keep his people, and so to justify and sanctify them through the Lord Jesus, that the church may be presented "a glorious church, without spot or wrinkle" Ephesians 5:27 on the Day of Judgment.

In the day ... - On the Day when the Lord Jesus shall come to judge the world; and which will be called his Day, because it will be the Day in which he will be the great and conspicuous object, and which is especially appointed to glorify him; see 2 Thessalonians 1:10, "Who shall come to be glorified in his saints, and to be admired in all them that believe."

1:8 Who will also - if you faithfully apply to him.Confirm you to the end. In the day of Christ - Now it is our day, wherein we are to work out our salvation; then it will be eminently the day of Christ, and of his glory in the saints.