New born babies know nothing of malice, guile, hypocrisy, envie or evil speaking, but we have all seen babies that are hungry. They want milk! They need milk to grow.
Like the newborn baby, we must desire the milk of God's word if we are to grow in our spiritual lives. Unlike the newborn, however, we do know about all those nasty things mentioned. As sinners these things are a natural part of our lives. We must consciously lay them aside. This is hard work. It takes diligence.
If we have been saved by God's grace, we have tasted that The Lord is gracious and as a result we will desire the milk of the word. If a baby has no desire for milk then the baby is sick or worse has no signs of life. If a person has no desire for the milk of God's word they are either spiritually ill or they were never saved to begin with and do not have life in Christ.
We must be careful in our judgement of others who may be going through a dry period in their Christian experience. It is easy to assume that someone is not really a believer if we are not seeing growth and desire for God's word. It is not our place to judge their hearts as we do not always know how God works. But we must be ready to come along side and encourage them.