We are truly saddened to hear about the abuse and manipulation you have experienced from someone you thought was a Christian friend and mentor. We will pray for you and address the issues at hand using biblical principles.
Firstly, it is clear that the person you described is not exhibiting the fruits of the Spirit, which are love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control. Instead, they are manifesting the works of the flesh, which include hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy. As it is written in Galatians 5:19-23 (WEB):
"Now the works of the flesh are obvious, which are: adultery, sexual immorality, uncleanness, lustfulness, idolatry, sorcery, hatred, strife, jealousies, outbursts of anger, rivalries, divisions, heresies, envyings, murders, drunkenness, orgies, and things like these; of which I tell you now, as I also told you then, that people who practice such things will not inherit God's Kingdom. But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faith, gentleness, and self-control. Against such things there is no law."
We must also address the fact that the person you mentioned is involved in an affair with a married relative, which is adultery, a sin clearly condemned in the Bible. As it is written in Exodus 20:14 (WEB):
"You shall not commit adultery."
Furthermore, the family of this person runs a cult masquerading as a church. We must beware of false prophets and teachers who come in sheep's clothing but inwardly are ravening wolves. As it is written in Matthew 7:15 (WEB):
"Beware of false prophets, who come to you in sheep's clothing, but inwardly are ravening wolves."
We will pray for your protection and deliverance from this dangerous individual and their accomplices. We will also pray for their repentance and salvation, as Jesus Christ desires all people to be saved and come to the knowledge of the truth. As it is written in 1 Timothy 2:3-4 (WEB):
"For this is good and acceptable in the sight of God our Savior; who desires all people to be saved and come to full knowledge of the truth."
Let us pray:
Heavenly Father, we come before You in the name of Jesus Christ, lifting up our beloved in prayer. We pray for their protection and deliverance from the dangerous individual they have described. We bind the spirit of abuse, manipulation, and stalking, and we loose the spirit of peace, safety, and freedom, in Jesus' name. We pray that You would expose the works of darkness and bring them to light, convicting this person and their accomplices of their sins and leading them to repentance and salvation. We also pray for the spouse and children of the married relative, that You would protect them and bring healing and restoration to their family. We ask this all in the mighty name of Jesus Christ, our Lord and Savior. Amen.
Finally, we encourage you to continue trusting in the Lord and leaning on His understanding. He is your refuge and strength, a very present help in trouble. Do not be afraid or dismayed, for the Lord your God is with you wherever you go. As it is written in Psalm 46:1 (WEB):
"God is our refuge and strength, a very present help in trouble."
We also recommend that you seek wise counsel and support from your local church and Christian community. They can provide you with practical help and guidance during this difficult time.