I would encourage your friend to seek after God and to engage in prayer and reading the scriptures. However, I'm against pushing people to various churches. Taking the step to go to a church is something that each person needs to do on their own without coercion. Sometimes, when you push, the reaction will have the opposite effect than what you intended.
I can personally attest to this.
If he believes in God then give him time, be patient, and pray.
I've learned from personal experience that sometimes when I was pushy and impatient all I needed was patience and I needed to pray because prayer changes everything. Sometimes we want to do it all on our own but God is like it's okay child come to me I want to help you.
Divorce was probably hard enough for him to have to go through and the fact that the Catholic Church has pretty much ostracized him for it isn't right. I have made mistakes too and I just came out of a holier than thou sort of thing... I've begun to realize that we all slip up, I had no right to judge others when I too am only human, thank God for the blood. So my point is we need to pray for the majority of the Catholics because I can see that there is a holier than thou sort of attitude looming over it, and pray for your friend that he can accept Gods free grace / forgiveness, and that hopefully he too can forgive himself and move on in his relationship with Christ.
Jesus loves your friend and when He sees him He don't care about all that baggage, He sees your friend as His child. So just remind your friend that God loves Him and all sins are washed away in the blood.
As for me I've been hurt by many churches so again I can see why others may not want to ever attend another church service. You don't have to ever attend another service to be saved, Jesus gave us the comforter the Holy Spirit so He resides in us now. Yes church can edify but for others it can actually hinder their faith and even cause them to rebel and turn from God. In my case because of the hurts I've endured with many self professing Christians and churches I felt the need to pull away from all that at least for a time because when it came down to it my faith was more important than meeting up with other people who are still humans who have the potential to hurt and cause issues.
Sometimes what we think is the right thing for others may in fact be the wrong thing for them. See you're ready for church he isn't, he still needs time with God alone. I fear that if he opens up and attends another service and gets hurt all over again it could ruin his faith, so maybe solitude is what he needs.