I don't see at all how you think that I'm implying that Christianity is based on rewards. That thought would never occur to me. ...... I don't know about other people, but I go to church to worship God. As it happens, I also tend to get something from it. And that's the way God designed it. However, the motivation should be to worship first. ...... God owes us nothing, but in effect, He does "owe" Himself the keeping of His promises.
Because the book of Hebrews spells it out, FK. It says that faith is hope. So, when we worship, we worship in hope. And what is that we are hoping for? Life-everlasting, salvation. Take that out and see how many people come to church to declare His glory. People go to church because they want something from God. People want to live. People want to believe this is not all there is to it. It is the hope that makes our faith meaningful. God is meaningful with or without us, whether we pray or not; whether we follow Him or not.