It would be hard to find any adult Catholic who does not have a loved one who has left the Catholic Church. It can be a very difficult thing to deal with. Here are some important things to remember whenever this happens.
God is infinitely more concerned and involved in the salvation of your loved one than everyone else put together. You are not alone in your love for this person and you are not the only one who wants them to come back to the Faith. The all powerful God the the universe is on the case.
The most important thing you can do is prayer and fast. Jesus taught how powerful prayer and fasting is. There are many things we may wish we could do or say, but the most important thing by far is prayer and fasting.
There is no magic book or CD you could give your loved one. Sure, there may be a book or CD out there that could help a little, but your loved one is a unique individual withe unique thoughts, feelings and experiences. As well, they may not be willing to read a book or listen to a CD.
Tell them once what you think about them not practicing their Faith. Make sure they know you love them and want what is best for them. Then leave it alone. Unless they come to you with questions or asking for advice, don’t keep hounding them. Just witness your Faith by how you live your life.
Encourage them to pray and ask God to show them if it is good that they left the Church. Again, don’t hound them, but just ask them once if they did pray, and encourage to give it an honest try.
You are not responsible for converting them back to the Church. God does that. Don’t confuse yourself with God. You witness with your words and deeds. You love them. God will do the rest.
Pray that God will put someone in their lives who will help them return to God. This is important for everyone, but particularly for parents. Mom and dad are not usually the person an adult child wants to listen to. A friend their own age, who they can relate to, is usually very helpful.
Understand that this is all part of God’s plan. Not that God wants your loved one out of the Church, but God may know that them leaving the Church for a while is necessary for them to return a more committed disciple of Jesus. Remember, Jesus let people leave Him if that is what they wanted to do. Many disciples left Him at the end of John chapter 6, because they did not accept the teaching on the Bread of Life. Jesus know they needed to go if they could not accept His teaching. However, it does not mean that many of them did not reflect and come back at a later time.
Be patient. God is patient with them… and with us. We must also be patient.