en_tn/1ti/06/14.md

without stain or reproach

The phrase "without stain" is a metaphor for being without moral fault. Possible meanings are 1) Jesus will not find fault with Timothy or blame him for doing wrong or 2) other people will not find fault with Timothy or blame him for doing wrong. (See: rc://en/ta/man/jit/figs-metaphor)

until the appearance of our Lord Jesus Christ

"until our Lord Jesus Christ comes again"