We are truly sorry to hear about the spiritual attacks you and your fiancé have been experiencing. We are here to pray and support you both in the name of Jesus Christ. Let's first address your need for encouragement and praying to God correctly. Know this, it is only in the name of Jesus that we have access to God. This is made clear in John 14:6 WEB
Jesus said to him, I am the way, the truth, and the life. No one comes to the Father, except through me.
Now, remember what James says about where our help comes from in James 5:13 WEB
Is any among you suffering? Let him pray. Is any cheerful? Let him sing praises.
Even when we face trials, as Jesus Christ has overcome them all, so to we will overcome through Him. Even in our weakness and fatigue He is there. This is made clear in 2 Corinthians 12:9 WEB
He has said to me, My grace is sufficient for you, for my power is made perfect in weakness. Most gladly therefore I will rather glory in my weaknesses, that the power of Christ may rest on me.
It is good that you recognize the source of the attacks. Remember, our battle is not against flesh and blood, but against spiritual forces. What you're experiencing is described in Ephesians 6:12 WEB
For our wrestling is not against flesh and blood, but against the principalities, against the powers, against the world's rulers of the darkness of this age, and against the spiritual forces of wickedness in the heavenly places.
In Mark 10:9 WEB, Jesus tells us:
What therefore God has joined together, let no man separate.
So we stand with you and pray for God's will, rebuke the enemy and pray for your marriage.
Heavenly Father, we come before you in the name of Jesus Christ, lifting up this couple who are under spiritual attack. We pray that You will intervene and rebuke the forces of evil that are seeking to destroy their relationship. We ask in Jesus name that you bring healing and restoration to their relationship. Strengthen their faith and trust in You, and fill their hearts with Your forgiveness, love, and peace. We ask that you bring clarity and guidance to their relationship making it clear if it is your will that they should be married and if so to bring about a Godly marriage that honors and glorifies You. We pray that You will restore what the enemy has stolen and that Your will be done in their lives. We ask this in Jesus' name, Amen.
We encourage both of you to put on the full armor of God as described in Ephesians 6:10-18 WEB and stand firm against the enemy's attacks. Continue to pray together, seek God's will, and trust in His promises. Remember, God is faithful, and He will not allow you to be tempted beyond what you can bear. He will also provide a way out so that you can endure it. We encourage you both to stay strong in your faith and seek God's purpose together. There is no other name by which we can be saved, so give thanks to Jesus for your salvation.