Mat 4:18  And Jesus, walking by the sea of Galilee, saw two brethren, Simon called Peter, and Andrew his brother, casting a net into the sea: for they were fishers. 
Mat 4:19  And he saith unto them, Follow me, and I will make you fishers of men. 

Joh 1:40  One of the two which heard John speak, and followed him, was Andrew, Simon Peter's brother. 
Joh 1:41  He first findeth his own brother Simon, and saith unto him, We have found the Messias, which is, being interpreted, the Christ. 
Joh 1:42  And he brought him to Jesus. And when Jesus beheld him, he said, Thou art Simon the son of Jona: thou shalt be called Cephas, which is by interpretation, A stone. 

There are a lot of puzzles in the bible. WE MUST BELIEVE GOD’S WORD. One Simon is Simon Barjona. This is the Simon who was fishing.

Mat 16:17  And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. 

One Simon is Simon Jona. This is the Simon who Andrew, his brother brought him to Christ. [Jona is a different word to Barjona.]

Joh 1:42  And he brought him to Jesus. And when Jesus beheld him, he said, Thou art Simon the son of Jona: thou shalt be called Cephas, which is by interpretation, A stone.

Cephas is a stone; Peter, below, is not called a stone: Christ is the rock.

Mat 16:18  And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. 

Cephas is called a pillar, not one of the twelve apostles.

Gal 2:9  And when James, Cephas, and John, who seemed to be pillars, perceived the grace that was given unto me, they gave to me and Barnabas the right hands of fellowship; that we should go unto the heathen, and they unto the circumcision. 

There are two sets of brothers both with the same name. One Peter is an apostle, one Peter is not. Read this verse carefully. Cephas is not one of the twelve Apostles. Peter from the fishing boat is one of the Apostles.

1Co 15:5  And that he was seen of Cephas, then of the twelve:

The bible is full of seemingly conflicting statements, and God has to reveal the correct answers. This is because to know God the Father, and Jesus Christ is to have eternal life; and most people would blaspheme the Holy Spirit, and go into the lake of fire which is the second death. Every human ever born will have a chance to attain eternal life. Most will get their chance at their resurrection back to humanity.