What did the cherubim symbolize in the tabernacle?
The cherubim symbolized a covering of God's mercy over the law contained in the box. Their wings met above the mercy seat, showing that divine mercy alone answers the law's demands. The law is demanding, but God's mercy provides the only way to satisfy it.
Les explains that the cherubim were two angelic-like beings, made of pure beaten gold, whose wings literally met over the middle of that little box. He teaches that those cherubim indicated a covering of God's mercy, and that God's mercy is the only thing that could answer to what was inside the box—the law. The law is so demanding, and there is only one way to come close to satisfying its demand: in God's mercy. That is why it is called the mercy seat. Les also connects this to Romans 3:23-25, where Paul writes that all have sinned and come short of the glory of God, and are justified freely by His grace through the redemption that is in Christ Jesus.