God has already done all that he can do for the salvation of fallen man.
Jesus in our name and on our behalf has fulfilled the law, Matthew 5:18 and abolished it, Ephesians 2:15 and in our name and on our behalf has reconciled us and the world unto God, 2 Corinthians 5:18, 19. All that is required of us is to accept what has already been provided for us as a free gift from God, Ephesians 2:8.
No one needs to be predestinated. No one needs to obey the law. No one needs to join the Catholic church. In Jesus Christ we have been justified, sanctified and redeemed, 1 Corinthians 1:30. We are perfect and complete "In Christ" Colossians 2:10.
Jesus has done it all and he did it perfectly. Renounce your worthless religion, your works, your obedience to the law, Calvinism and trust in Christ alone. When you do, God will give you his Holy Spirit and you will be born again, 1 Peter 1:23.
Jesus saves and he saves to the uttermost, Hebrews 7:25.