"God was NEVER the head of the Catholic church and there never will. Jesus Christ is the Body of church and He is the Head of the church."
Jesus Christ was the founder of the Catholic Church. Jesus is part of the Trinity, id est, God HAS ALWAYS BEEN and ALWAYS WILL BE the head of the Church. Jesus also promised His Church that it will always be under His protection.
Matthew 16:18-19
"And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it. I will give you the keys to the kingdom of heaven. Whatever you bind on earth shall be bound in heaven; and whatever you loose on earth shall be loosed in heaven."
Matthew 18:15-18
""If your brother sins (against you), go and tell him his fault between you and him alone. If he listens to you, you have won over your brother. If he does not listen, take one or two others along with you, so that 'every fact may be established on the testimony of two or three witnesses.' If he refuses to listen to them, tell the church. If he refuses to listen even to the church, then treat him as you would a Gentile or a tax collector. Amen, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven."
The Church has authority on Earth
Luke 10:16
"Whoever listens to you listens to me. Whoever rejects you rejects me. And whoever rejects me rejects the one who sent me."
Christians are to be united in His Church
Romans 16:17-18
"I urge you, brothers, to watch out for those who create dissensions and obstacles, in opposition to the teaching that you learned; avoid them. For such people do not serve our Lord Christ but their own appetites, and by fair and flattering speech they deceive the hearts of the innocent."
1 Corinthians 1:10
"I urge you, brothers, in the name of our Lord Jesus Christ, that all of you agree in what you say, and that there be no divisions among you, but that you be united in the same mind and in the same purpose."
The Church is the Body of Christ
John 15:1-11
"I am the true vine, and my Father is the vine grower. He takes away every branch in me that does not bear fruit, and everyone that does he prunes so that it bears more fruit. You are already pruned because of the word that I spoke to you. Remain in me, as I remain in you. Just as a branch cannot bear fruit on its own unless it remains on the vine, so neither can you unless you remain in me. I am the vine, you are the branches. Whoever remains in me and I in him will bear much fruit, because without me you can do nothing. Anyone who does not remain in me will be thrown out like a branch and wither; people will gather them and throw them into a fire and they will be burned. If you remain in me and my words remain in you, ask for whatever you want and it will be done for you. By this is my Father glorified, that you bear much fruit and become my disciples. As the Father loves me, so I also love you. Remain in my love. If you keep my commandments, you will remain in my love, just as I have kept my Father's commandments and remain in his love. I have told you this so that my joy may be in you and your joy may be complete."
In Acts 9:1-6
"Now Saul, still breathing murderous threats against the disciples of the Lord, went to the high priest and asked him for letters to the synagogues in Damascus, that, if he should find any men or women who belonged to the Way, he might bring them back to Jerusalem in chains. On his journey, as he was nearing Damascus, a light from the sky suddenly flashed around him. He fell to the ground and heard a voice saying to him, "Saul, Saul, why are you persecuting me?" He said, "Who are you, sir?" The reply came, "I am Jesus, whom you are persecuting. Now get up and go into the city and you will be told what you must do."
Jesus tells Saul (in the above) that Saul is persecuting Jesus.
Jesus also warns His Church it would always be persecuted and warned His followers against false prophets who would try to spread dissention among the Christians and lead them against the Faith.