Um... are you going to explain how this couldn't possibly mean anything other than Peter is the first pope and the Catholic church is absolutely correct in all things forever and ever?
May I say something? In the Law we see the Lord making an everlasting covenant with the children of Israel. They are to walk in His Ways and abide in His Law, and He would bless and protect and prosper them. We see their history, all the idolatry they partook in, and how the Lord rejected most of them, even led them into captivity. We get to the time of Jesus. These people that the Lord made an everlasting covenant with, this same Lord called them the children of the devil, cursed the nation, and said that they would see Him no longer til they say Blessed is He who comes in the name of the LORD. What happened? A remnant broke off of Israel, they were received in the New and Perfect Covenant, as well as all in the nations who believes and receives. Paul comes to let us know that it is not the children of Abraham's flesh that are the children of the promise, but the children of Abraham's faith. Seems pretty clear, right?
Let's say Cephas was in fact the first Pope of the Universal and Apostolic Church. The Lord blessed Him because of His faith, and because of the revelation God gave him. The guy was very poor, it is assumed he never had a home like His Lord. He didn't dwell in a palace or wear fine clothes or jewels, He was a poor fishermen who spent his life proclaiming the Good Tidings of the Lord to the Circumcised. Look at what he wrote, look at what he preached.
Now compare Peter to the Popes we know of today. Do they match? No.Just as the Jews forfeited their inheritance and favor with God because they did not continue in the faith of Abraham, so Catholics do the same if they do not continue in the faith of Peter. The Lord gave the children of Israel an everlasting covenant, yet He rejected them and cursed the nation and gave that covenant only to a remnant, even speaking that being a child of Abraham was not enough to receive favor with God. John spoke that, so did Paul.
Just because you are a Pope, or just because you are a Catholic and has been baptized in the church and has done all the rituals, it does not mean you are in favor with God. The Lord spoke, only he who does the will of His Father will enter the kingdom of Heaven, and only those who do the will of His Father, who hears the word of God and do it, are His brothers.