You say that as if there's nothing else he should be concerned about and because you have a heavy weight on your heart because of these morality issues. I'm disgusted by animal abuse and discrimination which are in fact things that are condoned in the Bible at certain points, there's also plenty of times where God has blessed people for murdering infants and murdering their brothers shortly after the law came.
We've all got different hierarchy's of morality but yours isn't more credible or righteous than mine or his.
Don't discredit him for that.
It sounds to me like you want to just love and accept these kids, but you have to understand that these are big issues that they are not going to cease to answer. There is hate in religion, there is hate in Christianity and hate coming towards the Christian religious values from the world— that's something you have to deal with.
Don't try to love them regardless of them annoying you, if you don't feel like you are already capable of loving them unconditionally then you're not cut out for it and you need to find a way to come to terms with the fact that they're asking these questions. They matter to them.
You also need to remember that they're not subject to agree with your answers, and your answers aren't necessarily correct either. But you need to figure it out with them, and you're allowed to have an opinion. Just remember that they're allowed to have theirs as well.