This is really interesting, because that means that what God holds as true worship can't come from singing or speaking, or from careful reading or studying. In fact, true worship can't even come from good deeds or intentions. True worship can only come from the spirit.
That means that you don't have to be smart, driven, outspoken or beautiful to relate with God. Spirit is what God is, so to worship Him in spirit means that you experience Him as He truly is: the living, breathing, moving God. Not as words on a page, a good idea or an historical figure, but as the alive and present God who lives within you! A gentle turn of our thoughts to His presence, a minute or two taken during a lunch or bathroom break to open ourselves up to Him; even these simple things mean more to God than all the worship music or wonderful sermons on the earth. God greatest desire is to relate to us in the most intimate and personal way; in a way that becomes, not just a part of our lives, but our lives!
Come to Him simply and openly. Lay aside fancy prayers or biblical commentary, and come to Him just as you are.