Self-knowledge or Brahma Gnana is common to all religions***

All is consciousness.  The whole universe is consciousness. From the consciousness, universe comes. When universe disappears, the consciousness still remains without form, time and space.:~ Santthosh Kumaar 

Bible says:~ “God is a Spirit, and they that worship him must worship him in spirit and in truth (John 4:24)”,  

Yazur Veda also says:~ “Nathasya prathima asityasya nammahastha (32.3)”, God has no image and His name is Holy. 

All biblical insights lead to non-dual Self-awareness. Self-Awareness is Christ consciousness.  Self –Knowledge or Brahma Gnana in the biblical sense is  ultimate  Truth or Christ.  The truth was not written down but was imparted orally to the chosen few.  

Sage Sri, Sankara ’says:~ "Kuruthe Ganga sahar gamanam Vratha paripal mathva dhanam. Gyana Vihine.Sarva Mathene.” Self-knowledge or Brahma Gnana is common to all religions.  There is nothing like One Gnana for a Hindu and another for a Christian. 

John 8:32:~  You will know the truth, and the truth will set you free.”  

Jesus said:~  "Know what is in front of your face, and what is hidden from you will be disclosed to you. (THE GOSPEL OF THOMAS- Saying 5)  

It means one has to know the world which confronts him confronts to realize his body and world are made of the same essence and that essence is Spirit (father).   

Even Sage Sri, Sankara says: one must first know what is before him. If he cannot know that, what else can he know or understand? If he gives up the external world in his inquiry, he cannot get the whole truth. 

VC- 63. Without causing the objective universe to vanish and without knowing the truth of the Self, how is one to achieve Liberation by the mere utterance of the word Brahman? — It would result merely in an effort of speech.  

Sri, Sankara says:~  VC~ 65. As a treasure hidden underground requires (for its extraction) competent instruction, excavation, the removal of stones and other such things lying above it and (finally) grasping, but never comes out by being (merely) called out by name, so the transparent Truth of the self, which is hidden by Maya and its effects, is to be attained through the instructions of a knower of Brahman, followed by reflection, meditation and so forth, but not through perverted arguments. 

"Jesus said:~"Those who seek should not stop seeking until they find. When they find, they will be disturbed. When they are disturbed, they will marvel, and will reign over all." (Gospel of Thomas 2) 

"The Kingdom of God is inside you and all around you, Not in a mansion of wood and stone.  Split a piece of wood and God is there, Lift a stone and you will find God." (Gospel of Thomas) 

1.According to the New Testament, Jesus said to his disciples: ‘To you it has been given to know the secrets of the kingdom of God, but for others they are in parables, so that seeing they may not see, and hearing they may not understand’ (Luke, 8:10). While speaking to the multitude in a veiled manner, ‘privately to his own disciples he explained everything’ (Mark, 4:34), and advised them not to ‘throw your pearls before swine’ (Matthew, 7:6). 

2. According to Clement of Alexandria (150-215 CE), ‘Mark’ preached three different gospels. The New Testament version was intended for ‘beginners’, but there was also a Secret Gospel of Mark for those who were ‘perfected’, i.e. initiated. Clement advised one of his students that the existence of this secret gospel should be denied ‘even under oath’, for ‘the light of the truth should be hidden from those who are mentally blind’. The third gospel was so mystical that it was not written down but was imparted orally to the chosen few (JM 120-1). 

When the seeker indulges in deeper self-search than he realizes the fact that, the experience of birth, life, death and the world are mere illusion created out of spirit or Brahman or Christ, the innermost self.