Knowing who Jesus is alone, won't be enough. We can say we know who he is, as Peter did. But then if we deny the work of the cross, it is then he must cast us out. Peter was first blessed by Jesus because he recognized who Jesus was. But then when he denied his death, read below the words Jesus had for him!
Bro. Blume pointed this out earlier in another thread, I am just sharing the scripture here.
Matthew 16:15 He saith unto them, But whom say ye that I am?
16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God.
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.
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.
19 And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
20 Then charged he his disciples that they should tell no man that he was Jesus the Christ.
21 From that time forth began Jesus to shew unto his disciples, how that he must go unto Jerusalem, and suffer many things of the elders and chief priests and scribes, and be killed, and be raised again the third day.
22 Then Peter took him, and began to rebuke him, saying, Be it far from thee, Lord: this shall not be unto thee.
23 But he turned, and said unto Peter, Get thee behind me, Satan: thou art an offence unto me: for thou savourest not the things that be of God, but those that be of men.
24 Then said Jesus unto his disciples, If any man will come after me, let him deny himself, and take up his cross, and follow me.
25 For whosoever will save his life shall lose it: and whosoever will lose his life for my sake shall find it.
26 For what is a man profited, if he shall gain the whole world, and lose his own soul? or what shall a man give in exchange for his soul?
27 For the Son of man shall come in the glory of his Father with his angels; and then he shall reward every man according to his works.
28 Verily I say unto you, There be some standing here, which shall not taste of death, till they see the Son of man coming in his kingdom.