‘If they are “born with it” then it must be a good thing. Why should I stop them?’
God didn’t make a production line for humans and leave it running, a few flaws in production but mostly ok. He designs each soul individually, in His image. God doesn’t make mistakes, humans make mistakes.
‘If we’re made in His image, and he doesn’t make mistakes then how do we make mistakes?’
We have free will, and through the original sin, temptation was introduced into the flesh. The flesh is reproduced by the flesh and while it still glorifies God to some degree, it does have flaws and temptation, scars of our war against or alliance with sin. We also tempt each other to sin, communities tempt us to sin, temptation from ‘the world’, which worships sin. And of course the devil who offered us temptation in the first place continues to enjoy seeing others fall.
If all the law is summed up in ‘love God’ and ‘love others’ then why should we stand up for what we believe even when the world says that its not love? Why do we try to stop others from wrong choices unless we are certain of the consequences? Because we want them to become all that God designed them to be. God designed perfection for them, because He loves them, so we should want to help the towards that perfection.
Disobeying God isn’t asking for tea when he’s given us coffee, its asking for instant when He’s offering espresso. He doesn’t give us rules to take away our choice or variation but because he wants the best for us.