This question starts off with a misunderstanding of who Christ is and what He has done for us. What I often tell my son when he asks, "do I have to?", is that we don't have to... we get to. When he asks if he has to clean his room, I remind him that cleaning his room is something he wants to do and needs to do, but through choices and laziness and bad attitudes, he forgot that cleanliness and order is the life he would rather have. Hopefully that anaology didn't make you cringe too much. Thankful people live differently. When we truly realize what God did for us, we want to change things up. There is also a significant misunderstanding in the commands of the Bible. They are parental in nature. Think of being told to brush your teeth and to go to bed early. Was that fun when we were kids? No! But as adults, some of us can't get to bed early enough. And after several root canals, I wish my parents had been much stricter with me. We have learned that our parents were looking out for us. God is looking out for us to. When He tells us how to treat others, how to live, and what choices should look like... He isn't rubbing His hands together and cackling like a control freak... He is being a good dad. And, the more we mature in Him, the more we realize how much He loves us and wants to protect us. But I feel like I have to answer a little more bluntly, so I'll sum up. We don't have to change, we get to. But to be thorough, if we don't change, then we likely don't have the relationship with Him that we need to have. The Bible says we die to ourselves. Our old lives end and new, changed lives begin when we accept Jesus through belief, repentance, and baptism. There is change, but it isn't tiresome, begrudging, forceful change. It's good news. It's happy and excited change. We are joyful in our union with God.