'Lord's' in the Bible

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

As long as we have life we are living to the Lord; or if we give up our life it is to the Lord; so if we are living, or if our life comes to an end, 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.

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