Romans 14:18 For he that in these things serveth Christ is acceptable to God, and approved of men.
English “serveth” emboldened in Romans 14:18 was translated from Greek verb 1398 douleuo meaning to voluntarily serve God as a slave by their covenant with God. There was a flesh Old Testament/covenant/contract between God and the Israelites. There is a spiritual New Testament/covenant/contract between God and “seven thousand” “chosen” “elect” “election”.
What Does The Bible Really Say? 