It's absolutely true that the more you sin, the more distant you grow from God, and your emotions/psyche suffer as a result. First of all, how exactly do people explain this? It's not imaginary. It's observable. It's a noticeable phenomenon.
Do people think that the people of old, the ones who didn't even understand racial equality, somehow sat around and studied people to determine which behaviors altered their thought processes to a state which just somehow didn't feel like they were emotionally connected to a higher power, and then take these miraculously scientifically accurate findings and make religious doctrine out of them? What purpose would they have in doing this? If they wanted "blind followers" who didn't "question things" as people today commonly think, couldn't they have just invented a religion without taking the time to make it line up with actual observable phenomena in our world that common people wouldn't even have been able to understand anyway? This is besides the fact that this kind of stuff would have been completely lost on the people spreading it from the beginning anyway.
And besides other inherent truths.
But anyway, the effect sin has on us is fascinating, especially considering how people typically perceive it. Unbelievers claim that in adhering to pre-written doctrine, we are being "enslaved" by it (as if the fact that it is pre-written somehow negates its inherent truth). In fact, that's not the case. We choose to follow God, to answer His call to us; younger people may sometimes be pushed into it by their parents, sure, but they ultimately make their own decision no matter what their parents push, no? So they too are free, in their heart, to choose God. At the end of the day, they are not forced by any person to believe one way or another. They choose whether to answer God's call or not. People are all free to do this.
The second reason that "enslavement" claim is wrong is that it's just misguided from the beginning. Sin is what enslaves us, not God. God lets us choose. A state of sin doesn't allow for choice, because the devil is always pushing it onto you anyway. Freedom from sin is the best choice. With God, you read His word which encourages you to do good for others, and the effects go on for a long time, if not forever. With sin, you watch pornography online (and inadvertently actually support a corrupt industry that mistreats its workers!), get nothing productive done with your time, and have a temporary high that you will only lose and want again sometime later, and again, and NEVER be truly satisfied! With God, your heart is warmed to love others, and to reach out to them and help them. With sin, you sit in your house seeking material goods, mostly for yourself that will just go away when you break them or your house burns down or whatever happens, still watching porn (and still supporting a corrupt industry that mistreats its workers!), and growing bitter towards other people, doing nothing but dragging other people down for no reason! You don't enjoy the hatred, you don't enjoy the temporary highs you get from supporting corrupt industries or buying material items. You want a permanent high, and keep sinning in hopes of finding it, but you don't.
In this way, sinning is a lot like hard drugs. I don't do physical drugs, but the similarities are clear anyway. It's bad stuff that will do really bad stuff to your psyche, maybe permanently, and depending how careless you are, might actually kill you, but at the same time, it's addictive. It looks fun. It'll make you look cool to other people. Hard drugs are bad for you for these same reasons. Superficially it's just stuff that "makes you feel good" or "helps you relax", or something (even though with physical drugs, you'll probably buy them from someone who doesn't know how to make them properly and you'll have a really bad time right from the beginning anyway!) but in the real world, they're deadly, are often a "gateway" to doing even worse stuff, are addictive, and will only leave you with a temporary high that you'll never be able to keep up without dying. The same happens with sin, but even though it does affect you physically/mentally in many ways, it's largely spiritual. And it's addictive, and you don't want to be addicted to that kind of stuff.
God sets us free from that. We're humans, we still mess up, but with God's guidance and salvation in Jesus Christ, we can turn down those drugs, we're not stuck in that addiction anymore. We see what leads to that permanent high everybody wants, and it's not anything sin can give you. Difficulties arise; the devil still tries to sell us, and others, his poorly-made drugs that he lazily concocted in his basement, but if we keep up that faith for one short lifetime, we'll have an eternity to be happy. Heaven isn't like drugs, that only work for awhile by deceiving your psyche but then leave you wanting more, it's a world of clarity and truth where goodness, and no evil, will be. That's the world we have when we get rid of those drugs we do in our hearts. And you can only do those drugs for so long before you die. Now is the time to get over that addiction. Turn to God. Turn to Jesus.
God bless you all, according to His perfect will. In Jesus' name. Amen.