Is oneness theology wrong

Hello, I think it is wrong. Listen, this is just my personal opinion, but think by yourself: How would you feel if your lover, who you trust, would cheat on you with other lover? I think it would not be very great. I believe in one religion, but I have read about the other religions very much and I can say that all religions are similar. I mean, we believe in God, we believe that there is someone who will save us after we will die, who will bring us better life, success and so on. This is my personal opinion.