1) Respect
John 12:20-22
Philip was a greek and should be a friend of these people. They wanted him to introduce Jesus ("Sir")
Matt 21 - The son addresses the father as "sir" as a sign of respect.
Even in schools to show respect to teachers.
- Calling the Lord as Sir/Lord is to show respect to Him and also by the lives we live, that dont bring shame to Him but glory and honour to Him
2) Title of ownership
Luke 19:28-33
The Lord has ownership over all things. John 1:3 , Col 1 :16, 1 Cor 6:19,20
- Therefore every part of our lives belong to Him
3) Sign of Allegiance
Acts 25:23-27
Festus could not judge Paul. So he asked King Agrippa to try Paul. So that he could write to his Lord, Caesar.
Lord here refers to a standard title to the emperor Caesar.