'Lord' in the Bible

Grace to you and peace [inner calm and spiritual well-being] from God our Father and the Lord Jesus Christ.

because I hear of your love and of your faith which you have toward the Lord Jesus and toward all the saints (God’s people).

no longer as a slave, but [as someone] more than a slave, as a brother [in Christ], especially dear to me, but how much more to you, both in the flesh [as a servant] and in the Lord [as a fellow believer].

Yes, brother, let me have some benefit and joy from you in the Lord; refresh my heart in Christ.

The grace of the Lord Jesus Christ be with your spirit.