Adam Clarke

Rejoice in the Lord - Be always happy; but let that happiness be such as you derive from the Lord. To write the same things - He means those which he had formerly preached to them or to other Churches, for he had but one Gospel; and we may rest assured that the doctrine of this epistle was the same with his preaching. For you it is safe - It is much better to have these Divine things committed to writing than confided to memory. By the latter they may be either lost or corrupted, by the former they will be preserved.