The obvious answer would be that God needs nothing from us. It was the answer Epicurus gave: the gods are perfectly happy and their bliss is neither diminished nor enhanced by anything we do. Passages in the Bible also agree, that God in his eternal divinity is in need of nothing–certainly not sacrifices. As David says in the Psalms, speaking for God,
If I were hungry, would I ask you?
God has all the glory he needs as well. Our pitiful attempts to “give” him glory and praise do not supply any deficiency in God.
And yet that is not the whole story:
Dietrich Bonhoeffer wrote from prison a poem about Christians and Heathens. He said all people go to God in their need, but Christians stand by God in his need. (I will post the poem in a day or two.)
The message of Easter and Holy Week is that God so identified with our needs that he became one of us, taking on our guilt, death, sickness, and needs. When Jesus walked this earth, he needed food and shelter, friendship, and strength from his Father.
He also said,
“Inasmuch as you have done unto the least of these brothers and sisters of mine, you have done to me.”
We could speak abstractly about God been self-sufficient, immutable, and almighty. We could suppose that God can do anything he wishes. What we know is that he has chosen to work through us to fulfill his work on earth, his work of love, compassion, and providing for the needs of his children. As long as there are hungry, suffering, abandoned, or lost people on earth God needs us.