We understand your urgency and desperation. Let's bring your request to God together, making sure it aligns with biblical principles. We are grateful to see this request is in Jesus' name.
Firstly, we must understand that while it's commendable to desire that someone becomes a born-again Christian, we cannot make anyone believe. God gives each person free will. We can, however, pray for them and share the gospel with them, and God can draw them to Himself. It is only by the name of Jesus that we can be saved. Salvation is the miracle that brings us into a relationship with God. Believing in Jesus Christ is the only way to salvation, the only way to God. Let's pray for this person's salvation and for God's will to be done in their life. Let's also remember that no one comes to the Father except through Jesus. Let's pray for wisdom as we witness to this person.
For there is one God, and one mediator between God and men, the man Christ Jesus. 1 Timothy 2:5 WEB
For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, Ephesians 2:8 WEB
Jesus said to him, I am the way, the truth, and the life. No one comes to the Father, except through me. John 14:6 WEB
Father, we lift up this person to You, asking that You draw them to Yourself and that they come to know Jesus as their personal Savior. Give us the wisdom and the words to share the gospel with them effectively. Help us to walk in love and patience as you do your work in their life. We ask for their salvation, not our will, but your will be done.
Regarding the unity and agreement you're asking for, we must remember that our unity should be centered around Christ and His purposes. We should desire to be of one mind, and that mind should be the mind of Christ. This kind of unity is a blessed thing and it is what we should pray for. Let's pray for God to guide both of your hearts and minds, giving you both discernment and wisdom, and bringing you together in Christ. Let's also pray for you both to be unified in Christ to do the will of God. Relationships should always be the same page when it comes to spiritual things, desiring to love and serve God together.
Only be alike minded, live in peace; and the God of love and peace will be with you. 2 Corinthians 13:11 WEB
Now the God of peace be with you all. Amen. Romans 15:33 WEB
However, we must address that it's not appropriate to pray for someone to desire or be attracted to you romantically. God does not work in that way. God does not manipulate people's emotions or desires to make them align with ours. Instead of praying for this person to desire you, pray for God's will to be done in both of your lives. Pray for God to guide your steps and this person's steps. Pray for God to prepare you both for the spouses He has for you, whether that is each other or not.
Delight yourself also in Yahweh, and he will give you the desires of your heart. Psalm 37:4 WEB
Don't be deceived, my beloved brothers. Every good gift and every perfect gift is from above, coming down from the Father of lights, with whom can be no variation, nor turning shadow. James 1:16-17 WEB
Let's pray for God to bless this friendship and guide it according to His will. Let's pray for purity and holiness in your interactions. Let's pray for God to prepare both of your hearts for marriage, and that you both would desire marriage. Let's pray for His timing and His will in your lives.
Finally, remember that true love is patient and kind. It is not selfish or demanding. It does not try to force its own way. It always seeks the good of the other person. Let this kind of love guide your interactions with this person.
Love is patient and is kind; love doesn't envy. Love doesn't brag, is not proud, 1 Corinthians 13:4 WEB
Father, please guide this friendship according to Your will. Prepare the hearts of both individuals for marriage, according to Your timing. Help them to interact with purity and holiness, seeking the good of the other person above their own desires. Give them both wisdom and discernment, and help them to live in unity centered around Christ. In Jesus' name, we pray. Amen.