John 4:23-24
"Jesus declared...Yet a time is coming and has now come when the true worshipers will worship the Father in spirit and truth, for they are the kind of worshipers the father seeks. God is spirit, and his worshipers mush worship in spirit and in truth."
~What does it mean to "worship in spirit and truth"? That's a good question, and I will make a feeble attempt to answer it. God wants us to love Him, to focus on how He wants us to live, to live that life. To "worship in truth" means that we must not be so hypocritical. We shouldn't spend hours praying if we can go do something to resolve an argument, etc. God wants us to worship, but most of all to live by his spirit, the spirit of his law. Also, God wants us to focus on Him and his work in our lives when we worship - no matter where we are (in a forest, our bedroom, the church...).
There's another good bible verse that talks about proper worship. It says that, when we come to give an offering at the altar, we should think if we have any grievances against our brother. If we do, we must leave our gift on the altar and go be reconciled with our brother. Then, we should return to the altar to give our gift. (I can't find where that verse is for the life of me! If you know, e-mail me!)
A quote from The Screwtape Letters by C.S. Lewis:
"What [God] wants of the layman in church is an attitude which may, indeed, be critical in the sense of rejecting what is false or unhelpful, but which is wholly uncritical in the sense that it does not appraise--does not waste time in thinking about what it rejects, but lays itself open in uncommenting, humble receptivity to any nourishment that is going....This attitude, especially during sermons, creates the condition (most hostile to [the devil's] whole policy) in which platitudes can become really audible to a human soul. There is hardly any sermon, or any book, which may not be dangerous to [the devil's pursuits] if it is received in this temper."
To me, this quote means that we must listen intelligently to sermons, etc. No one has all the answers, but many Christians have a lot of wonderful ideas. We must almost unconciously sift through these ideas and concentrate on the ones that ring true to the bible. We must see worship time as a time to learn, and want to get everything out of it that we can. I enjoy going to church because I'm bound to learn something. Sometimes, you hear a lot of repetitive or far-off stuff, but that's okay. You can find a lot of gems among those. The most important thing to focus on during worship, or time with God, is growth. We are called to chomp down every morsel of nourishment that we can. When we begin to think with such an attitude, things that we've heard 20 times before can really impact us. So try it--be open to God's word, really.
(The Screwtape Letters was written by Lewis, a prominent Christian author of this century. This book is a series of "letters" from one devil to another. Through this novel, Lewis illustrates the ways that evil spirits in the world try, and sometimes suceed, to lead us away from God. I highly recommend this book!)