What do you think is on the heart of God? His passion. His heartbeat.
According to the readings to day, it's not so much about the religious functions as it is the relational functions. Not sacrifice but steadfast love. Not burnt offerings but knowledge of God.
Steadfast love is the Hebrew word chesed (also spelled hesed, with a hard 'h'). It means the covenant love that God has for His people. God desires that back. He loves us. He wants to be loved back. Now that isn't in a Sally Fields Oscar speech kind of way. God's not up there wondering if we like Him, if we really like Him. His love sets us free to love Him for all eternity. And that's what's on His heart - that we love Him like He loves us for all eternity. Relationship.
The knowledge of God is not the knowledge about God. Don't confuse the two. Plenty of people know a lot about God without knowing the God they study. But our God is a God who longs to be known by His people. He is passionate about revealing Himself and relating to those that belong to Him.
Not religion. Relationship.