To understand how the devil is able to perform spectacular signs and wonders at Medjugorje, it may be helpful to review a few basic principals from Sacred Scripture as follows:

According to Revelation 12:7–9, a great war broke out in heaven and Satan was thrown down to the earth along with his legions of fallen angels. Today, this vast army of demonic entities prowl around like a roaring lion looking for the ruin of souls. To protect ourselves from Satan's deadly presence, God has given his beloved children the power of the Holy Spirit and an assignment of holy warring angels to stand guard over us night and day.

Because Christians are expected to live in a fallen world of darkness, God has given us the wisdom and resources we need to protect ourselves, and also the power to drive darkness out of our lives through our authority in Christ. A good example of how Catholics can protect themselves from evil comes from a man who dedicates his home to Christ.

To begin this process, the man would simply focus his mind and heart to God and say a simple prayer. To make this step more concrete, the man can place anointed rocks around the perimeter of his property. He could also drive stakes annointed with oil into the ground to establish a protective barrier around his property. He could also enclose his property by sprinkling holy water and saying to the spiritual realm, "I hereby dedicate this property to the Blessed Trinity—God the Father, the Lord, Jesus Christ and the Holy Spirit." 

This man could also ask for a spiritual canopy to be built around his property. He could ask Jesus to send holy warring angels to stand guard over his property day and night. He should also invite the presence of the Lord, Jesus Christ, and the Holy Spirit to dwell with him inside his house. Before this can occur, the man would need to live a holy and obedient life. It would not be possible for the man to commune with the Lord, God Almighty inside his home if he was watching sex and violence on television every evening or committing the sin of idolatry by praying to false gods.

For example, if the man's teenage son brought a Ouija board into the basement and started playing with it, attempting to communicate with spiritual entities other than the Blessed Trinity, then the man's spiritual canopy would be breached. In the spirit realm, there could be thousands of angelic warriors standing guard over the man's property, but once the teenage boy commits the sin of idolatry, the demons would have the right to enter the premises and answer the boy's prayer request.

In the spirit realm, the demons would say to the angelic warriors, "Move aside! The boy wants to communicate with us! He is calling out for our guidance!" Because God allows the devil and his legions of fallen angels to roam the earth looking for the ruin of souls, the angelic warriors would stand aside. The demons would have access to the man's house to interact with his teenage son.

When the teenage boy was finished playing with the Ouija board, the demons would still have the right to remain in the man's house until the boy repented of his sin, broke all agreements with the devil through his sin of idolatry, and removed the Ouija board from the premises.

Now just imagine what would happen to the man's spiritual canopy if a group of Satanists were allowed to enter the basement and perform child sacrifices. After killing innocent babies, the Satanist would then invoke curses over the property as they buried the children's remains in the basement underneath the concrete slab. If this were to occur, the sins of the Satanists, along with the curses and buried remains, would give the devil the right to manifest even more power and presence inside the man's house.

The same spiritual principles that apply in this situation also apply to Medjugorje. If the devil has the ability to manifest his power and presence inside a man's house because his teenage son has been playing with the Ouija board, just imagine what would happen at an apparition site that has been built on the remains of demonic sacrifices committed by the Ustasha Regime. 

When thousands of solders destroyed Christian and Orthodox churches, tortured religious sisters, monks and priests, and buried men, women and children alive in the Golubinka pits, it gave the devil the same power over the region as if thousands of Satanic rituals had been performed on the land. When the Ustasha Regime exterminated 750,000 Serbs and threw women and children into the Golubinka pits alive, it brought a curse of darkness over the land, giving the devil power to perform more signs and wonders at Medjugorje than at any other apparition site in the world.

Another reason why the devil is allowed to perform spectacular signs and wonders at Medjugorje is because the property has been consecrated to spiritual entities other than the Blessed Trinity. The people who visit Medjugorje do not go to have an encounter with God the Father, the Lord Jesus Christ, or the Holy Spirit; rather they go to have an encounter with spiritual entities operating under the names Gospa, Queen of Heaven or the Immaculata.

Pilgrims who want to have a deeper encounter with the Lord Jesus Christ go to Jerusalem. They visit the Holy Land to see where the Christ Child was born in Bethlehem. They go to experience a small town where Jesus grew up in Nazareth or to see where he was baptized in the Jordan River. They want to see where the Lamb of God was crucified on the cross of Calvary for the forgiveness of their sins. Because Medjugorje has been consecrated to the Gospa, the people who visit Medjugorje go to have a spiritual encounter with an entity other than God Himself.

Another reason why the devil can perform powerful signs and wonders at Medjugorje occurs through the sin of idolatry. When thousands of pilgrims show up and pray the Rosary for the purpose of invoking an encounter with the Gospa, it has the same effect as if thousands of New Age practitioners said prayers attempting to invoke an encounter with Isis or the Ascended Master Mother Mary. According to the Catechism in section 2708, the Rosary is a meditation on the life of Christ.  It is not to be used in voodoo ceremonies to invoke Momba spirits, or at apparition sites to invoke encounters with the Gospa.

Breaking the devil's stronghold over Medjugorje would occur the same way a man would cleanse his house after a group of Satanists performed sacrifices in his basement. The first step would be to offer prayers of repentance for the sins that were committed by the Ustasha Regime. Mighty prayer warriors would need to take authority over the curses imparted upon the land and break them in the name, power and authority of the risen Lord, Jesus Christ. The church militant would need to pray for the salvation of souls that were tortured and executed in the Golubinka pits. We would also have to ask God to send angelic warriors to spiritually cleanse every aspect of Medjugorje as we plead the shed blood of Jesus to wash over the adjacent countryside.

Please consider praying the following prayers for Medjugorje and sending this request to prayer groups around the world.

1. Please offer prayers of repentance for the forgiveness of sins committed by the Ustasha Regime who tortured and executed more than 750,000 Serbs in the vicinity of Medjugorje between 1941 and 1945.

2. Please pray for the salvation of souls, the men, women and children that were thrown alive into the Golubinka pits.

3. Please ask God to send a special assignment of warring angels to cleanse the land surrounding Medjugorje and to break all curses off of the surrounding countryside.

4. Please ask God to destroy the devil's ability to operate at Medjugorje and to destroy all curses and devices that give demonic powers the ability to operate at this apparition site.

5. Please pray that God will prevent people from visiting Medjugorje and warn those who are considering a future trip.

6. Please pray for millions of Catholics who visit Medjugorje so that they will be protected from demonic deception and that their spiritual eyes will be opened.

7. Please pray for the seers of Medjugorje (Ivan Dragicevic,  Marija Pavlovic-Lunetti, Jakov Colo, Ivanka Ivankovic-Elez, Mirjana Dragicevic-Soldo and Vicka Ivankovic-Mijatovic), that if they are not acting in complete accordance with God's will, the Holy Spirit would convict them of their sins and speak truth into their lives.