The greeting of me, Paul, with my own hand, which is the sign in every letter: this is how I write.

 At the end Paul adds his autograph to authenticate his letter. "Look," he says, "this is what my handwriting is like. Mark it, so that you will know it again." And then, with the truth expounded, with praise and rebuke lovingly intermingled, he commends the Thessalonian Church to the grace of the Lord Jesus Christ. 