Children learn from their parents, and faith is no different in this regard. If you value your faith, your children are more likely to value theirs. If you want your children to love their faith, you need to show them that you love yours. Go to worship. Pray at home. Make it clear that faith is a large part of your life. 

Despite how many parents raise children with a “do as I say, not as I do” mentality, children are far more likely to live life in a “monkey see, monkey do” fashion. If your faith is hypocritical, and children tend to be better at spotting hypocrisy than many adults, your children will grow up believing that faith is empty words or that what matters in religion is what you say, not what you do. Either version of so-called faith will fall apart as children age. If you want your children to love their faith, you need to demonstrate why it matters. Live your own life according to the tenets of your faith and do so with a smile. If you act like religion is a necessary evil, your children will start looking for ways to avoid it. To picture how far they will go to avoid faith in that case, think of how much work they put toward avoiding other necessary evils like tidying their room or doing their math homework.