What does 1 Corinthians 16:21 mean?

Paul and other New Testament writers often dictated their letters to an amanuensis, someone hired to write while they spoke the words of the letter. Until computer technology became widespread, it was common for people trained in writing—or typing—to record the words of someone else. Winston Churchill, for example, wrote the first drafts of his own books in much the same way.

Paul regularly took up the pen himself to write a few lines. This might have been to validate that the letter was really from him (2 Thessalonians 3:17), to make his sign-off more personal (Colossians 4:18), or emphasize a strongly-worded point (Galatians 6:11). His choice to write in his own hand at the end of this letter would have accomplished all three of these. His malediction—in contrast to a benediction—in the following verse contains a strong curse against those who do not love the Lord.