The Bible calls us to be like children in two specific ways: First, Jesus says that unless we approach the kingdom of God as little children, we will never enter it (Matthew 18:3). That is, we are to approach the kingdom of God with a simple, childlike trust in God. The second way in which the Scripture directs us to be children is, “In regard to evil be infants, but in your thinking be adults” (I Corinthians 14:20).
R.C. Sproul