Look up "Greek six types of love"

 

Make sure he can articulate his feelings, separate them, and not get confused.

"One has choices.  Make sure you choose wisely.  Take your time to sort them out.  No rush to make a decision right now.  As you grow older, you will be wiser.

"Something you can do does not mean something you should do.  Nothing is free in this world, everything comes with a price.  Make sure you know what the prices are.  Don't fool yourself into thinking you can get away with not paying it."

There are children's versions of the Bible.  Find one that fits his reading level.  Kids nowadays are spiritually vacant, and that emptiness causes them to seach for fulfillment, with anything they find.  This is not religion.