First of all, this is a legitimate question. As a parent you should continuously question your role in your child’s life, no matter if they are 3 or 30. No one has parenting perfection. 
I will answer this question pretty directly, you haven’t done anything wrong. This is a common fear among parents, especially parents that come from strict upbringings. For instance, if your parents are from a small Korean province and migrated here 30 years ago their belief system is quite different from an American upbringing. Tradition and the roles of men and women are ingrained in their minds as foundational rules, rules that cannot be broken. Like the law of gravity on Earth, what goes up, must come down. Likewise, if you are male you must marry a woman. 
There are many variations of this. As children we must also be as tolerant as we are asking our parents to be. This is an opportunity to learn for most parents. They simply need to be educated in a progressive society. Most parents know that societal rules are changing. They know they are way behind the curve and have no idea what to do. Its like that law of gravity being suddenly broken, you drop a rock and it goes up instead of down, its going to be shocking. So, be patient with them and open to answering questions. Don’t be discouraged when they are disbelieving of your sexuality. Just hold firm, but lovingly. 
Parents, you didn’t do anything wrong. Your children’s character is a result of you, not their sexuality or skin color or hair color. They are predetermined. Now, your child can choose to engage in straight or gay sex. We have that choice, where we dont have the choice is if we like it. Fathers, your straight, right? If homosexuality is a choice then by that same logic you could sleep with a man AND enjoy it. Seem unrealistic? That’s because it is. You didn’t choose to like women, it just is. Its the same for lesbian and gay and bisexuals. We didn’t choose it, it just is. Trying to be straight for a gay man is dangerous territory pyschologically and has potential for very serious mental health problems. 
For example: Tell a white man he must be black to be right. The idea is ridiculous, but imagine the confusion for a mind to try and actually practice such a thing. You can see your clearly white, but in order to please anyone, you must at least not admit your white, or want to be white and that every day you must get a little darker. You don’t need to be a Doctor to see the danger here. Its the same concept for your homosexual child. 
I will warn you, your children are precious and you will regret not accepting them for their sexuality. Those who repress their sexual identity encounter depression, suicide, anger, anti-social behavior and many others. You are of much more benefit to them as an advocate then an enemy. 
Remember that they need help figuring this out to. For some, many, coming out is scary and liberating. Its amazing and stressful, all at the same time. Its a beautiful road that is full of surprise, love and dangers. Your child cannot choose to be straight. You cannot teach them to be straight. You cannot teach them to be gay. You can teach them self acceptance or self hate. You can teach them good coping mechanisms or bad ones. How do you handle tough and scary situations? Do you go smoke a cigarette, maybe a joint, drink a beer, do you get angry and lash out? They will too, regardless of what you tell them, its what you SHOW them they’ll remember. Show them tolerance and love and they’ll do the same. 
As for the religious aspect, this is touchy but I will address it briefly. Remember that The Bible is written by God, Likewise the Quran. What is God? What does The Almighty stand for? Is it hatred and intolerance? Did not God send atonement so that each man and women will work out their own salvation? Your job is to love, not condemn. You profit God nothing by putting a wedge or ultimatum in between God and one of His children. In fact, by doing so you will face a harsher punishment. God knows all, He doesn’t need you to speak for Him, He doesn’t need you to point out another’s anything. “Work out your own salvation with fear and trembling”. Leave the judgement to God because we’re no good at it anyway. Do the fun stuff with your kids, no matter the ages, just love them. You’ll do well in front of the Father to have simply loved your children through everything. 
As a parent if you need help, its OK. You are not alone. My mother has been through it all. I would encourage anyone struggling to email her at [email protected]

With Love
Jeff Utnage 823469