God made all men, and He deserves our service. The Word of God says that the whole duty of man is to fear God and keep His Commandments. The keeping of the Word of God is a major way to serve to God. Submitting your body and mind to God is a great service to Him. You also serve God by working in His Vineyard. There are different gifts, ministries, operations, and callings in the Church the Body of Christ. You serve God by worshipping Him in Spirit and Truth."