18. Since Jesus Christ Himself continually imparts strength, as the head does to the members of the body, and as the vine does to its branches - a strength which always precedes, accompanies, and follows their works, and without which these cannot in any way be welcome and meritorious - that justice of ours is the same as God's justice, because it is imparted by God through Christ's merit. However, far be it from a Christian to trust or boast in himself and not in the Lord, whose goodness towards men is so great that He wills that the things which are His gifts should be their merits, Ibid. Chapter 16.