Jesus must reveal himself to you for you to understand his existence.
Luke 10:22-23 All things have been delivered to Me by My Father, and no one knows who the Son is except the Father, and who the Father is except the Son, and the one to whom the Son wills to reveal Him.” Then He turned to His disciples and said privately, “Blessed are the eyes which see the things you see.
The disciples spent time with Jesus yet only understood what they had when he left them.
Luke 24:31 Then their eyes were opened and they knew Him; and He vanished from their sight.
There must be grace for you to understand spiritual things hence you hear people calling on radio discussing Christianity with their canal understanding.
It’s not the years you have been reading the bible, it’s the revelation that comes from reading that brings us closer to Him.
Mark 8:17 But Jesus, being aware of it, said to them, “Why do you reason because you have no bread? Do you not yet perceive nor understand? Is your heart still hardened?