"Brethren, be not children in understanding: howbeit in malice be ye children, but in understanding be men." (1 Corinthians 14:20)
The Christian life is entered by the new birth so that everyone who is genuinely born again must begin as a spiritual babe. "Except ye be converted, and become as little children," said the Lord Jesus, "ye shall not enter into the kingdom of heaven" (Matthew 18:3).
Furthermore, they should continue to be as innocent children insofar as "malice" (Greek kakia, literally meaning "wickedness" or "evil") is concerned. This is an attribute which should diminish, not grow, in a believer.
The sad truth, however, is that many born-again Christians remain spiritual babes in attributes which should characterize strong men and women of God. Paul equated the term "babes in Christ" with carnality, characterized by "envying, and strife, and divisions" (1 Corinthians 3:1, 3). Paul also speaks of those Christians as "children" who are "tossed to and fro, and carried about with every wind of doctrine" (Ephesians 4:14). He urges each one to be "speaking the truth in love," so that we "may grow up into him |Christ| in all things" (Ephesians 4:15).
Spiritual growth, of course, can come only through spiritual food and spiritual exercise. "As newborn babes, desire the sincere milk of the word, that ye may grow thereby" (1 Peter 2:2). "But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil" (Hebrews 5:14).
Christians should become mature, both in understanding and in behavior. The last reference to growth in the Bible applies to each Christian: "But grow in grace, and in the knowledge of our Lord and Saviour Jesus Christ" (2 Peter 3:18). HMM