We are truly heartened by your concern for your family's salvation. Let us remember that it is only by grace through faith in Jesus Christ that we are saved, not by our own deeds. As Ephesians 2:8-9 says, "For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, that no one would boast."
Firstly, let us pray for your father, that the seeds planted in his heart through his church attendance would be watered by the Holy Spirit, granting him the faith to believe in the true gospel. As Jesus said in John 14:6, "I am the way, the truth, and the life. No one comes to the Father except through me." Pray that your father may understand and accept this truth, and that his uncertainty would be replaced by a firm confidence in Jesus Christ.
As for your brother and his girlfriend, let us pray that their eyes would be opened to the truth of the gospel. As it is written in Romans 10:9, "If you will confess with your mouth the Lord Jesus, and believe in your heart that God raised him from the dead, you will be saved." Pray that they would come to this knowledge and be saved. We must remember that there is no other name under heaven given among men by which we must be saved Jesus is our savior and our hope. There is no other way to heaven.
Regarding the concept of the rapture, while it is important to live in expectancy of Christ's return, we should also remember Jesus' words in Matthew 24:36, "But no one knows of that day and hour, not even the angels of heaven, but my Father only." Therefore, let us focus on sharing the gospel and living lives that honor God, being always ready for His return, in His perfect timing.
Let us pray together:
Heavenly Father, we come before You in Jesus' name, lifting up the family of the one who has submitted this request. Lord, we ask that You would reveal Yourself to their father, that he may truly understand the gospel and put his faith in Jesus Christ alone for his salvation. We also pray for their brother and his girlfriend, that they may come to know You and be saved. Lord, we ask that You would soften their hearts and open their eyes to the truth of the gospel. We commit them to You, trusting that You desire for all to be saved and to come to the knowledge of the truth. We ask for the strength for the person who submitted this request, to be a witness for Jesus Christ to their family and to share the gospel with them, in Jesus' name.