Finally, bretheren, pray for us, that the word of the Lord may have free course, and be glorified, even as it is with you: And that we may be delivered from unreasonable and wicked men: for all men have not faith. But the Lord is faithful, who shall establish you, and keep you from evil. (2 Thess 3:1-3)
It is God’s mystery, He that is almightly, to invite mere humans as His co-workers with Him. Paul understood this, and it made him tremble. Therefore this request for prayer for them, so that the word of the Lord may work as it must. We are His living letters, the Scripture needs to be re-written within our lives, letter by letter. God who is faithful can do it within us and keep us from all evil.