I don't know if there's a God or if there is not. To me at least is irrelevant. Masturbation will hardly affect you physically, but psychologically will really affect you. It won't be nothing dramatic, but days will become weeks, and weeks months, and months years. The reason because it will affect your mind is that masturbation leads to porn, and porn leads to masturbation, and that cycle will worsen with the time. Your sexual psychology will depend on porn to be aroused. In other words, you will rely on fantasy to get aroused. Your penis will get used to your hand, to the grip of it. Without knowing you are digging your own grave. Because your sexual mind will demand something different. At first you will get aroused by a woman havinf sex with a man. Then that will just not be enough. Then you will look for lesbic action, then threesome, then orgies, then 30 guys cumming on a girl's mouth. But what happens when you have girlfriend? Wife? Lover? You will have sexas usual. But one day you will start having performance issues. Maybe stamina, maybe erection problems. You won't care that much until it happens twice, maybe three or ten times. Then your confidence will start to fall, and you go for the easy fix. "I am only 25, I can't posibly have erection problems". And you buy some pils, Viagra, Cialis, you name it. It will restore your confidence, and it will actually work for a few weeks, but after that you will notice that the problems are still there. Guess what? You fucked up your mind. It is not your body. your body is perfectly fine, but not your mind. Your mind is broken. Your body is so used to masturbation, to porn, that a normal woman will just... not be enough. The psychologycal part of sex is the most important aspect of sexuality. While the physycal part is only 5% of it. My advice? Leave porn for good. That is a fantasy that provides you with a deformed reality. Stop masturbating and have sex. And don't forget that you have programmed your body to react to certain things for 10, 20 or maybe more years. Can it be reverted? Maybe. Just start programming your sexual mind with the right input. Meditate a lot, workout. Learn how to live a life without stress even when the world that surrounds you is full with it. Save you form yourself. Unlike women, guys need to get it up if you want to have fun. The hand does not care if you have a weak erection. You will get off anyway, but while doing that you will be fucking up your life.