for flesh and blood has not revealed this to you, but
My Father who is in heaven.”
Here, Jesus contrasts “flesh and blood” knowledge with Truth which is revealed by God (and of course, Jesus is Truth [John 14:6]). The two are as different as night and day. In the matter of flesh and blood knowledge that is obtained from human, earthly sources, we may have reason to boast in our ability to study, investigate, reason, and decide. This is the Tree of Knowledge.
In the case of revelation, we have definitely no room to boast, for revelation is simply that which is revealed to us from heaven by the Lord. We cannot work to obtain it nor do we merit it. Additionally, no man may give it to us. Its source is God working in us through His Holy Spirit. This is the Tree of Life.