My mother's absurd belief

My mother is a Christian.She is seventy years old. Several years ago, she went out every often, almost everyday, and was busy coping some reading material every day. When we asked her what she was doing, she didn't tell us. Gradually, we found out she didn't go to church anymore, and didn't read Bible. She was cheated into believing a very absurd belief by some people. She believed that Jesus has come alive to the earth. The Bible was out of date. The new Jesus has written something new for people to read. If you are a real Christian, you should follow the new Jesus and if you betray the new Jesus, you will be punished. She has a lot of this kind of absurd idea. We tried very hard to pursuade her to give this wrong idea, but it's no use. My father quarelled with her almost everyday and enough fought with each other. My father often came to me for help. I don't know what to do, please help me. Thank you very much.