Be a true witness; preach the true doctrine.

1 Timothy 1:15
It is a true saying, in which all may put their faith, that Christ Jesus came into the world to give salvation to sinners, of whom I am the chief:
1 Timothy 1:16
But for this reason I was given mercy, so that in me, the chief of sinners, Jesus Christ might make clear all his mercy, as an example to those who in the future would have faith in him to eternal life.