Everyone's ay-ya-ya-ya-ya; they go: I love all of that, give it to me, pump that music up, lets it get it going, I love it all! But it's got to go deeper than just that. It's got to go right into the heart. I love it, it's highly expressive! Anyway, let me give you some reasons why the heart's so important...
#1) The heart is the center of your identity.
Proverbs 23:7 - "as a man thinks in his heart, so he is."
The way you think about yourself determines the identity you'll live out. When we got born again, we received a new identity. We've got the identity; but we still live out of the old, because we haven't yet been changed in our thinking, in our heart belief structures yet. So the person who's rejected, after they've come to Christ, still struggle with rejection; until the truth of their acceptance is established in the heart, and they can say: I am accepted, I am a child of God - I know it in my heart. So the heart is the center of your identity - who you are. As you think in your heart, so you are; and it says: "a man's heart is like water, it answers to the heart". In other words, just as you see your reflection in the water, so you see a man's heart - you'll see what they're really like. We get caught up with what's external, with the giftings and abilities of people, or the appearance of people, all the external trappings - and we get overwhelmed with that, and fail to look at the heart. Pastors and leaders must look at the heart of people. We must become heart specialists, because that's the thing that God is interested in.
#2) The heart is the focus of God's attention. 1 Samuel 16:7, where Samuel is sent to find a new king who will rule Israel; he went to the house where David's father was, and he got all the sons out, and the first one comes out alive - He's tall and good looking. He said: this must be the king; but this is what God said to him. He said: I have rejected that man; and the word 'rejection' is a very strong word, meaning: I have utterly set that man aside as not qualified for this role. Now the prophet, he looked a good man, but to God... and then He said this: "for man looks on the outside, but God looks on the heart". What God saw inside him, in his heart, was pride and arrogance - someone He couldn't use as king.
They brought all the sons out, and he thought: this is the one, this is the one, this is the one... and then he gets to the end... what the heck, what's going on here? But God had told him there's a son, so he says: is there anyone else here? They said: oh yeah, there's David, but we've got a problem with David. You know, there's a real question about how he was born, and there's a whole shame around his life; and actually, we don't really include him in the family. We've put him out there where he's in danger with the wild animals, because actually we don't really see him being part of the family. He said: bring him in. They brought him in. He said: that's the man; and this is what God said to David: "this is a man after My own heart".
So God has a heart, and this is what He said about David. See, we know David, lots of things about David that you know - you look at the failures and mistakes, and all the things; but God looked on his heart. So what was there about his heart, that God says: this man, I really love. He's a man after My own heart, who will fulfil my will in this generation. So David, what it means to be 'a man after the heart of God', means: his pursuit, in worship, was to discover the desires of God. Most people pursue God to get something; but he pursued God to find out what God likes - and when he found out what God likes, he totally overturned the whole religious and worship structure of the day; transformed it.
Moses had established the pattern of worship. He got it on the Mount. He was shown what to do. He was given the pattern on the Mount; and there's this young upstart who comes along, and he says: we're changing it all! You've got to have some pretty strong authority to be able to change something that's a historical tradition for the church's worship. He got rid of the whole lot, except the ark; and then he established 24 hours of worship, singing, praise, prophetic ministry. He stepped, because he saw God's heart; he saw way into the future, what God had in mind, what He really wanted; and that these things were all just symbols - they had no power in them, whatsoever.