'Serve' in the Bible

For your servant vowed a vow while I was living at Geshur in Aram, saying, ‘If the Lord shall indeed bring me back to Jerusalem, then I will serve the Lord.’”

Besides, whom should I serve? Should I not serve in the presence of his son? As I have served in your father’s presence, so I will be in your presence.”

“You have also delivered me from the contentions of my people;You have kept me as head of the nations;A people whom I have not known serve me.