'Serve' in the Bible

For thy servant vowed a vow while I abode at Geshur in Syria, saying, If the LORD shall bring me again indeed to Jerusalem, then I will serve the LORD.

And again, whom should I serve? should I not serve in the presence of his son? as I have served in thy father's presence, so will I be in thy presence.

Thou also hast delivered me from the strivings of my people, thou hast kept me to be head of the heathen: a people which I knew not shall serve me.