"Every Word of God is pure; He is a shield to those who put their trust in Him." Proverbs 30:5
"My God, my rock, on whom I take refuge, my shield, and the horn of salvation, my stronghold and my refuge, my savior; you save me from violence. I call upon the Lord, who is worthy to be praised, and I am saved from my enemies." 2 Samuel 22:3-4
The Lord is always faithful to His Word. But we must have faith and trust in Him. Don't look at the enemy...look towards our Lord. If we get consumed by our problems...no matter what they are, then our eyes are no longer on the Lord and that is what the enemy wants. Stand strong in His Word. The best weapon you have is to pray for that person with love and forgiveness.
I am praying for you on this.