Jesus teaches in John 3 that when we become Christians, we are born again, the Spirit gives birth to spirit. In 1 Peter 2:2, it says “like new born babies, crave pure spiritual milk, so that by it you may grow up in your salvation.”
How often do we see ourselves as spiritual babies? Do we continually seek to learn, grow in spiritual development and maturity?
Some Christians are still being fed milk because they are not ready for solid food (1 Corinthians 3:2). Or there are some others who stopped growing and stay stagnant (John 15:1-4).
One can profess to be a Christian for 20 years, yet has little knowledge of God nor possess an authentic relationship with Him. His faith is ritualistic, having information but no revelation, not experiencing the presence and power of God.
One can never know God enough or experience Him fully; it is a lifelong endeavour. Are you still learning and growing?