for every animal of the forest is mine,
and the cattle on a thousand hills.
The reason that he doesn't need the stuff that we have, is because it is already His. He is Lord of all. He is over all things, and by Him all things exist. When we choose to serve Him and offer things to Him, we are simply acknowledging His Lordship. We are being thankful for all that He has given us, and offering back to Him.
Everything that you see today, belongs to God. No matter how perverted or twisted man has made it, it ultimately belongs to Him. One day, every knee will bow and every tongue will confess this great Lordship. Why not start today?