John is summoned into heaven to see God in His glory. God can only be described in human terms that are inadequate to do the scene justice. The description is similar to descriptions in Isaiah 6 and Ezekiel 26. As in those descriptions, God is praised by all the heavenly beings.
We look forward to the day when we can join in this praise of God. Living in this world, we see God鈥檚 glory in only limited ways and, thus, can only praise Him in limited ways. One day, we will be in His presence and praise Him forever!