God isn't after your hands, but your heart. There's nothing useful you can offer Him, but He chooses to take delight in the heart that loves him. It is the only thing that He established as an acceptable offering, and so it is the only act of worship which has any meaning. All worship coming from this heart of love to God and guided by His Spirit is good and lovely and true; and all that does not is self-serving, self-glorifying and self-deceiving.