Little children put pretty much everything that comes to hand into their mouths, and as we mature as children of God we ought to learn to discern what is spiritually healthy and good for us and what is not. Anyone can be infected with pinworms in their intestines, but it is young children who are most susceptible because they often put contaminated food or fingers in their mouth. Age alone does not equal spiritual maturity, for Hebrews 5:12-14 says: "For
though by this time you ought to be teachers, you need someone to teach
you again the first principles of the oracles of God; and you have come to need
milk and not solid food. 13 For
everyone who partakes only of milk is unskilled in the word of
righteousness, for he is a babe. 14 But solid food belongs to those who are of full age, that
is, those who by reason of use have their senses exercised to discern both
good and evil."
Over time children in the ancient world were weaned from breastmilk to solid food, and it is important to point out the milk from a mother is not sterile. From what I have read it is actually a living substance that contains all the necessary nutrients and microbes that promote the health and development of infants, strengthen their immune system and provide a healthy gut. A time comes when the physical needs of babies and toddlers are met with solid food as they grow up. Those who are born again by faith in Jesus are to acquire their spiritual nutrition from the word of God that is profitable for babes and those of "full age" alike. As a baby hungers for milk from his mother or a person hard at work looks forward to a healthy lunch, so Christians are to satisfy their spiritual hunger by God's word they feed upon and put into practice.
It is important God's word provides the acceptable standard for what we will choose to receive. Just because a book is written by a pastor or a worship song is sung by a well-known Christian artist, it does not follow it is guaranteed to be biblically sound. As we grow older we learn to put the food we plan to eat to simple tests like how it looks, if it smells off or if there is something moving in it that should not be. Sometimes we are not quite sure if the milk is fine or if leftovers are safe to eat, and in most cases it is good to be cautious to avoid what will make us sick or not agree with us. Recently I bought an album by a Christian band that I have enjoyed very much, however there is a line I refuse to receive. Just because lyrics rhyme or are catchy does not mean they are all true and accurate according to scripture.
As followers of Jesus, we must be discerning of what we read, sing or assume must be true lest we fall into error. It is good when we recognise rotten doctrines and heresies before we drink them down, and by reason of use determine wholesome scripture interpretation in fellowship with other Christians. Better than microbes, we have the Holy Spirit who dwells in our hearts and guides us into all truth. He convicts of sin, of righteousness and judgment, helping us to walk in love and grace towards all. We will never mature beyond our need for guidance, direction and wisdom from God's word, for they are the words of life that promote spiritual growth, health and fruitfulness.