How do I deal with my non-Catholic parents trying to tell me how to raise my son?

It's sad that your parents don't know the true Christian Church founded for them by Jesus Christ. However, all decisions about raising your child are yours (you and your husband), and that means not subjecting them to potentially harmful ideas, which would include false religious beliefs. Anyone who has contact with your children must respect your decisions concerning how you wish them to be raised, and anyone who refuses to do so necessarily has to be kept away from them. This has nothing to do with honoring or not honoring your parents. It has everything to do with fulfilling your responsibilities as parents. Your decision doesn't necessarily have to be final. Of course they want to spend time with their grandchildren, and when the subject comes up again you can speak with them again and hopefully reach a mutual understanding that will allow them to do so without violating your parental rights. God bless you.