'Service' in the Bible

who are Israelites; whose is the adoption, and the glory, and the covenants, and the giving of the law, and the service of God , and the promises;

I beseech you therefore, brethren, by the mercies of God, to present your bodies a living sacrifice, holy, acceptable to God, which is your spiritual service.

For this cause ye pay tribute also; for they are ministers of God's service, attending continually upon this very thing.