Amidst a discussion with Nicodemus in John 3:9-15, Jesus unveils that while he left the realm of heaven during his incarnation, he never left the state of having direct communication and fellowship with the Father. This is truly remarkable! All that being said, think about the kind of revelation that Christ brings, in that it’s all based on first hand experience. In other words, he reveals what he himself has known and what he himself has seen from the Father, as in John 1:18 No one has seen God at any time; the only begotten God who is in the bosom of the Father, He has explained him.
Again, compare this kind of knowledge with Nicodemus’ we know of v.2. How pathetic! Along the same lines are those who claim to have received heavenly visions and revelation since the Son of Man has physically ascended back to the Father’s right hand. No wonder Paul writes what he does in Gal. 1:8 But even if we, or an angel from heaven, should preach to you a gospel contrary to what we have preached to you, he is to be accursed! So how fast should we disregard anyone who thinks they know things or have heard things from the Lord if it contradicts or even attempts to supplement what the Son of Man has revealed!
It is obvious from this passage in John 3 and many others, that the Only Begotten Son has brought the clearest and most complete revelation (Heb. 1:1-3).