I can understand the Pope serving as the head of the Church but he claims the title of representative of God on Earth that is where my main confusion lies.
He doesn’t claim the title, it was given to him:
Isaiah 22:20-24
20 In that day I will call my servant Eliakim the son of Hilkiah,
21 and I will clothe him with your robe, and will bind your girdle on him, and will commit your authority to his hand; and he shall be a father to the inhabitants of Jerusalem and to the house of Judah.
22 And I will place on his shoulder the key of the house of David; he shall open, and none shall shut; and he shall shut, and none shall open.
23 And I will fasten him like a peg in a sure place, and he will become a throne of honor to his father’s house.
24 And they will hang on him the whole weight of his father’s house, the offspring and issue, every small vessel, from the cups to all the flagons.
Here we have Eliakim being made steward, and given all authority of the house of David. Now compare this to what Jesus says to Peter:
Matthew 16:16-19
16 Simon Peter replied, “You are the Christ, the Son of the living God.”
17 And Jesus answered him, “Blessed are you, Simon Bar-Jona! For flesh and blood has not revealed this to you, but my Father who is in heaven.
18 And I tell you, you are Peter, and on this rock I will build my church, and the powers of death shall not prevail against it.
19 I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.”
So here we have Jesus (who is a Davidic king) making Peter His steward, giving him the keys of the kingdom, and the power to bind and loose things in heaven and on earth. The Jews in Caesarea Philippi would have been quite familiar with the scripturally referential words deliberately used by Jesus.
Jesus also promises in this establishment of the Church that “the powers of death shall not prevail against it” because of this foundational rock He is building it upon. Jesus promises that the fidelity of this Church He is establishing will not be conquered by Satan.
Now you can look at the history of the Church and see that the vast majority of the popes have been holy, courageous, spiritual men who have carried out their duties wonderfully. You can also see some popes who were quite sinful and an embarrassment. Does this mean the Church was corrupted?
To answer this question, we only have to look at our first pope. Who did Jesus choose to give this massive responsibility to?
Was it someone with unshakeable faith?
No… It was the one of “little faith” who got scared when he was called out to walk on the water and sank.
Was it the only apostle why actually had the courage to stand at the foot of the cross with His mother?
No… It was the one who He knew would deny Him three times and flee.
Was it the one who loved Him most?
No… It was the one who He asked multiple times if they loved (agape) Him, and the most they could offer back to Him was that they only “loved” (philios) Him.