'Lord's' in the Bible

Be not slow in your work, but be quick in spirit, as the Lord's servants;

For whether we live, we live unto the Lord; and whether we die, we die unto the Lord: whether we live therefore, or die, we are the Lord's.

That you will take her in kindly, after the way of the saints, as one who is the Lord's, and give her help in anything in which she may have need of you: because she has been a help to a great number and to myself.

Greetings to those Christian workers, Tryphaena and Tryphosa; also to dear Persis, who has laboured strenuously in the Lord's work.

Give my love to Rufus, one of the Lord's selection, and to his mother and mine.