Rom 12:1 I Beseech you therefore, brethren, by the mercies of God, that you present your bodies a living sacrifice, holy, acceptable to God, which is your reasonable service
In the light of God giving His all for us, we should give our all to Him. God is looking for our physical sacrifice, not just spiritual. Serving God will always call for sacrifice. There's always a price to the will of God. No great destiny comes cheaply. It's impossible to serve God without being separated to Him, set apart for His exclusive use. What we present to God needs to work. A phone with a dead battery is useless. A car without wheels doesn't do what it's designed for. Paul says this is reasonable - that we live each day on the altar for God. The fire of God only falls on us when we're on the altar!