'Service Of The Lord' in the Bible
This is why I have sent Timothy to you. He is a dear child of mine, in the service of the Lord, and one on whom you can depend, and he will help you to keep in mind my methods in the service of Christ Jesus, which I follow everywhere in every church.
It is true, food is meant for the stomach, and the stomach for the food, but God will put an end to both of them. But the body is not meant for immorality, but for the service of the Lord, and the Lord is for the body to serve.
Therefore, my beloved brothers and sisters, be steadfast, immovable, always excelling in the work of the Lord [always doing your best and doing more than is needed], being continually aware that your labor [even to the point of exhaustion] in the Lord is not futile nor wasted [it is never without purpose].