Brothers, stop thinking like children. In regard to evil be infants, but in your thinking be adults. (1 Cor 14:20 NIV)
Like newborn babies, crave pure spiritual milk, so that by it you may grow up in your salvation, now that you have tasted that the Lord is good. (1 Pet 2:2_3 NIV)
Jesus taught his disciples to be “wise as serpents and innocent as doves” (Matthew 10:16). Christians are called to be pure and without guile, but not naive about the world or mankind. With regard to sin, inexperience is a good thing. Tasting sin can never satisfy anyone, and can never improve the disciple, but even a taste can do great damage. No one needs to be scarred by fire to learn to avoid flames.
Nevertheless, a child must be informed about fire to know that there is danger and that fire is not to be played with. Consistent instruction from a loving but firm source should be sufficient. The word of God presents this kind of firm and loving instruction about evil, and is to be craved by the child of God, like a baby craving milk. This craving should never diminish, the young innocence of appetite for the best thing there is. And as the milk provides growth, strength is gained, but innocence (purity) is not diminished, rather it is complemented by growing maturity in salvation.
The child of God can and should at the same time be an infant, innocent toward sin, and also mature, adult in thinking, discernment, decision making, work, and relationships. Infants are able to express happiness and unhappiness, but aren’t able to communicate in precise ways, or control their reactions to circumstances, or accomplish much for themselves or anyone else. Those who have grown up and put an end to childish ways (1 Corinthians 13:11) are called to a life of love and self_control, not ruled by their own emotions or appetites, or the behavior of others, but ruled instead by the spirit of Christ (1 Corinthians 13:1_10, 2 Corinthians 13:5_7).
Even if we have not yet attained the goal of adult maturity with infant innocence, we can and should picture it and move toward it (Philippians 3:10_13), consuming the milk and working on personal growth through practice-applying the word in our own lives (Hebrews 5:14). We should try to see ourselves as we can be by God’s work within us, and choose that perfected self as a goal to take hold of. The image of what we can be (the image of Christ, Galatians 4:19) may be only a dream now, a dim image in a glass (1 Corinthians 13:12), sometimes distorted by childishness, but with the help of God it will become a reality, as “all of us, with unveiled faces, seeing the glory of the Lord as though reflected in a mirror, are being transformed into the same image from one degree of glory to another; for this comes from the Lord, the Spirit” (2 Corinthians 3:18 NRSV).