I guess it's perspective because god and religion mean different to different people. But in general terms, changing religions is absurd to me for whatever reasons (It's just my opinion). When you grow upto 20 plus years, you are bound to form some belief system in yourself. So if someone says that I am changing my religion it only means two things to me. It's either
1. You are already associated with the new belief system long back and you are now just making it official. These are people who have been studying and probably practicing the new religion for a while and find it enlightening or something. So they are not actually changing their religion because they never really followed their original religion
or
2. You are bluffing yourself. "I love my spouse so much that I am going to switch to his/her religion" That's a lie because you cannot change your belief system for someone else. You may try to look like a new person from outside, but inside you are same person with the same old beliefs.
I am an atheist and suppose I befriended a beautiful, charming, caring (all what I ever wanted in my wife) christian/muslim girl who wanted to marry me but also wanted to change to her religion, I would say no. It's also a bit insulting to expect a person to change their religion, because it means you have no respect for what the person believes in. If I married a girl of different religion, then it would be ideal if she followed her religion and I followed mine, and I would probably take her to the church/mosque etc and celebrate her festivals as long as there is no messing with each other's heads about religion
