'Else's' in the Bible

Who are you to criticize someone else's servant? He stands or falls before his own Lord and stand he will, because the Lord makes him stand.

My one ambition is to proclaim the gospel where the name of the Messiah is not known, so I don't build on someone else's foundation.

The spiritual person evaluates everything but is subject to no one else's evaluation.

I mean, of course, his conscience, not yours. For why should my freedom be determined by someone else's conscience?