Mankind has made some pretty cool sounds throughout history, from the terrifying battle cries of ancient armies to the stunning symphony of thousands of voices singing together. We make noises that can travel too: if you stood outdoors on a perfectly still day, you could be understood clearly 200m away. That’s nothing though: there’s a language called ‘Silbo’, used by the Spanish-speaking inhabitants of the Canary Islands, which can be understood up to 5 miles away. To top it all, there’s even one recorded case of a human voice being detectable at a distance of over 10 miles, across still water at night! A while ago I heard a sound that blew me away. It was during a large worship celebration: one song had just ended… The instruments died out, the crowd grew silent. Suddenly the only noise in the place was a loud, out of tune groan coming from the front row. I looked for the source of the sound and saw a woman with tears streaming down her face, her arms stretched out to heaven, just pouring her heart out to God. This worshipper was deaf and had no idea that the rest of us had stopped singing and were now looking at her. She was just going for it, expressing an uncontainable passion for Jesus, which echoed around the meeting place. To be honest, it was not the most musical sound I’ve ever heard. But strangely, it was among the most beautiful: we were listening to the sound of her heart. A few seconds later, her friend nudged her in the side and she stopped. That moment has remained burned on my memory because it reminds me of a principle that is core to our theology of worship: God listens to the sound of the heart. Your heart is amazing: it is roughly the same size as your fist, but it’s a little mean-machine. Today yours will probably beat 100,000 times and over the average lifetime will clock up a whopping 2.5 billion beats. Your heart is hard at work: in fact when you’re resting, it’s still exerting twice as much relative strength as your leg muscles do when they’re sprinting at full speed. Your heart has two main jobs: firstly, to pump your blood into your lungs to be re-oxygenated, then to pump it out round your body. Your blood does a round trip, via the central station of your heart, once every 20 seconds. While our physical hearts are vital to keeping us alive, God is also pretty big on the condition of our ‘spiritual hearts’. “Above all else, guard your heart, for it is the wellspring of life” (Prov 4:23). To God, the heart of the matter is the matter of the heart: God looks at our hearts (1 Sam 16:7), searching us (Jer 17:10), probing and testing every motive and attitude. He knows what’s going on in them (Luke 16:15), has set eternity in them (Ecc 3:11) and created them as the place of interface with him. There is good reason for this: whatever has our heart’s affection instantly has our worship (Matt 6:21). The common understanding in both the Old and New Testaments was that the ‘heart’ was the control centre of a person’s being: all yours mind, ideas, thoughts, motives and decisions flowed from here. It is with our hearts that we look for God (Deut 4:29), love God (Deut 6:5), serve God (Josh 22:5), meditate on him (Ps 19:14), hang onto his word (Ps 119:11), trust in him (Pr 3:5), do the will of God (Eph 6:6), love others (1 Pet 1:22) and pour out our worship to God (Ps 62:8). What happens if your hearts just not in it? How can we be heart-felt, when we feel like we’re having a spiritual heart attack? A healthy heart pumps in two directions: it pumps in and it pumps out. Likewise, our spiritual hearts will pump out whatever we’re breathing into our spiritual lungs. Jesus breathed on his disciples saying, “receive the Holy Spirit” (John 20:22) and we need to be breathing in that breath. Keep your God-breathing regular: if we stop breathing in, we’ll faint. If we keep breathing away regularly, we’ll find our hearts pumping away for God. In the Old Testament, God promised to “revive the heart of the contrite” (Isa 57:15) and pointed forward to a time when he’d be offering heart transplants: “I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone and give you a heart of flesh.” (Eze 36:26) Now here’s the transplant, which God offers us at the cross: we give Jesus our old hearts, in whatever condition they’re in. In exchange, he gives us a new heart. But there’s more… this heart comes fitted with the Ultimate Pacemaker: Jesus comes to make his home in us (John 14:23) by living in our hearts (Eph 3:17). This is the mystery of “Christ in you, the hope of glory” (Col 1:27) and the source of strength for us to be able to keep on running for God. With God living in our hearts, by in the person of the Holy Spirit, we are being renewed day by day on the inside (2 Cor 4:16). Now with this new Jesus-heart, we pump out worship as love for God and love for others. God-life flows through all that we are. Our new hearts become our main instrument for worshipping God: we’re to ‘sing and make music in your heart to the Lord’ (Eph 5:19). When we're worshipping together, I try to imagine Jesus walking among us, listening to each of us with one of those doctor’s stethoscopes that filter out all the noise and amplify the heart. But Jesus doesn’t put his stethoscope away when the singing finishes on a Sunday. He’s listening to the sound of the heart at work on Tuesday morning; he’s listening to the sound of the heart when we’re out with our mates on a Friday night. Long after any songs you sing come to an end, the sound that continues to echo around the throne room in heaven is the sound of your heart. Al Gordon