We understand your heart's desire for your friend to come to Christ, and we will join you in prayer for his salvation. However, we must address that the Bible teaches us to flee from sexual immorality, which includes relationships outside of marriage between a man and a woman. As it is written in 1 Corinthians 6:18, "Flee sexual immorality! Every other sin that a man may commit is outside the body, but whoever commits sexual immorality sins against his own body."
Let us pray for your friend's salvation and for God's will to be done in your relationship. We pray that if it is God's will, He may transform your friendship into a godly courtship that honors Him, leading to a marriage that reflects Christ's love for the Church. As it is written in Ephesians 5:25, "Husbands, love your wives, even as Christ also loved the assembly, and gave himself up for it."
Heavenly Father, we come before You in the name of Jesus Christ, asking for the salvation of our dear sister's friend. Open his heart to receive the good news of the Gospel, that he may believe in Jesus Christ and be saved. We also pray for their relationship, that it may honor and glorify You, Lord. If it is not in accordance with Your will, give them the strength to part ways and trust in Your plan. In Jesus' name, we pray. Amen.
May God guide both of you according to His will, and may you find peace and comfort in His sovereignty. Remember the words of Romans 8:28, "We know that all things work together for good for those who love God, for those who are called according to his purpose." Trust in His love for you both, and continue to seek Him with all your heart.