I have read your article on the Six World Religions with great interest. I am sure you receive many emails, so I will keep this short. Could you please send me your thoughts on the essential differences between Catholics and Christians. My son is about to marry a Catholic, and I cannot fully justify to him my concerns.
Well, you're asking the right person, since my husband and I were both raised Catholic! Of course, there's a difference in expression between U.S. Catholicism and elsewhere in the world, but the basic beliefs are the same.
First of all, you should know that there are born-again Christian believers in the Catholic church. You should also know that the gospel really is there in the Mass, and in the catechism teachings that children and converts receive. Ray and I are grateful for the foundation of spiritual truth that we received from the Catholic church: that God is one God in three Persons, that Jesus is the Son of God, that He died on the cross for the sins of the world and was raised on the third day, and that He's coming back.
What we DIDN'T receive was the personal aspect: that we needed to personally receive the grace-gift of salvation. We were taught, instead, that being baptized a Catholic was enough to bring us into God's family. We were taught that Jesus opened the door to heaven, so to speak, but it was our responsibility and our good works that would get us there. So it was Jesus PLUS our good works that might result in salvation. But there was no assurance of salvation, just a vague hope that our good deeds would outweigh our bad deeds when we died.
If I were you, I would gently and lovingly have a conversation with your future daughter-in-law, and ask her the great question, "If you were to die tonight, and you were to stand at the gates of heaven, and God said, 'Why should I let you into my heaven,' what would you say?"
If she says anything other than, "Because Jesus died on the cross for my sins," then she is trusting in her own self or in the Catholic Church, and not Christ. You might ask her why Jesus had to die. If we could do anything to get us into heaven, why would Jesus have to die a horrible death? Wouldn't that be a terrible waste?
Sometimes people will say, "Because I'm a Catholic." We were taught that salvation is only found in the Catholic church. I would respond, "Where does that idea (that being a baptized Catholic is a "free pass" to heaven) come from? How do you know it's true?" Claiming to be a member of any organization is just another way of trusting in human merit and good works instead of what Christ has done FOR us.
I think that a lot of Catholics actually believe that it's "Jesus plus me." If you were to ask her, "Do you believe Jesus is the Son of God? Do you believe He died on the cross for YOUR sins?" you might discover she has intellectual assent to the truth of the gospel. You might then want to gently explain that in the Bible, God calls us to actively TRUST in Christ and not just believe in our heads what is true. The demons, after all, also believe that Jesus is God's son and that He died for mankind, but that doesn't change their hearts.
One other thing. If and when, Lord willing, you have grandchildren, you will have some marvelous opportunities to teach the truth about Jesus to them, and it's amazing how parents can be reached through their children. Pray a lot, and ask the Holy Spirit to give you a green light to talk about spiritual things for which He has prepared her heart. The Lord bless you and keep you!