The whole earth is mine.--Exodus 19:5
The silver is mine and the gold is mine.--Haggai 2:8
I own the cattle on a thousand hills--Psalm 50:10
Everything God made belongs to Him. Everything.
Because He loves us, he gives us some of it and, from that portion, we are to give some back, and thus worship and honor Him.
He is not joking about this either:
Bring the whole tithe into storehouse...and see if I will not throw open the floodgates of heaven and pour out so much blessing that you will not have room enough for it.--Malachi 3:10
He's designed a perfect system, really.
He makes stuff; He gives to us; we give back, and so on unto infinity.
But there's one catch.
Some of what we have, He does not want.
Bring me a denarius. Whose inscription is this? Repay unto Caesar what is Caesar's and to God what is God's.--Mark 12:11-12
God does not want us to give Him what did not come from Him in the first place.
WAIT A MINUTE!
Doesn't everything belong to God?
Yes, it does. Everything He made.
But didn't He make everything?
Hmmm... Think about it. What you have that did not come from God?
Actually, the list is quite long:
Should I go on?
As it turns out, we have plenty of things that God did not make, does not own, and does not want. We cannot ever dedicate those to Him. He will not accept them.
And His response to our attempts to do so looks like this:
Trouble, trouble, and more trouble.
It's all about motive. Just ask Cain and Abel.
God says, Give back my best and I will give you even more.
Try to give what is not worthy and you will be stuck with it.