Whom I serve from my forefathers - Being born a Jew, I was carefully educated in the knowledge of the true God, and the proper manner of worshipping him.
With pure conscience - Ever aiming to please him, even in the time when through ignorance I persecuted the Church.
Without ceasing I have remembrance of thee - The apostle thanks God that he has constant remembrance of Timothy in his prayers. It is a very rare thing now in the Christian Church, that a man particularly thanks God that he is enabled to pray for Others. And yet he that can do this most must have an increase of that brotherly love which the second greatest commandment of God requires: Thou shalt love thy neighbor as thyself. It is also a great blessing to be able to maintain the spirit of a pure friendship, especially through a considerable lapse of time and absence. He that can do so may well thank God that he is saved from that fickleness and unsteadiness of mind which are the bane of friendships, and the reproach of many once warm-hearted friends.
I thank God, whom I serve from my forefathers - Paul reckoned among his forefathers the patriarchs and the holy men of former times, as being of the same nation with himself, though it may be that he also included his more immediate ancestors, who, for anything known to the contrary, may have been distinguished examples of piety. His own parents, it is certain, took care that he should be trained up in the ways of religion; compare the Philemon 3:4-5 notes; Acts 26:4-5. The phrase “from my forefathers,” probably means, after the example of my ancestors. He worshipped the same God; he held substantially the same truths; he had the same hope of the resurrection and of immortality; he trusted to the same Saviour having come, on whom they relied as about to come. His was not, therefore, a different religion from theirs; it was the same religion carried out and perfected. The religion of the Old Testament and the New is essentially the same; see the notes at Acts 23:6.
With pure conscience - see the notes at Acts 23:1.
I have remembrance of thee in my prayers night and day - see the notes at Philemon 1:3-4.