The Gospel came to me through a revelation of Jesus Christ

" Now I want you to know, brothers, that the gospel preached by me is not of human origin.
For I did not receive it from a human being, nor was I taught it, but it came through a revelation of Jesus Christ."  (Galatians 1: 11 - 12)

The entire Gospel was revealed to Paul by Jesus Christ.  We learn the faith by catechesis starting from home, in school and especially in the Liturgy all our life long.  Not Paul.  Paul did not make any effort to learn the Gospel.  Christ delivered the message to him as a gift.

Christ promises the revelation of the mysteries of the Kingdom to the childlike.  Although we learn the faith, there are many mysteries we cannot understand.  But if we become childlike, Jesus Christ will reveal the mysteries of the Kingdom to us.  St. Therese, the Little Flower is an example of this truth.  She died at the age of 24.  She never attended high school but she is one of the 35 doctors of the Church.  She was taught by Christ Himself.