Breakfast, lunch, and dinner are a normal part of the day. We all revolve our days around eating food. You probably wouldn't think of going without physical food for a week or even a day, would you? Food is necessary for physical life. Without food, we become weakened and eventually become ill. Just as this occurs, lack of spiritual food produces the same results in our spiritual lives. Our culture tends to consider people "spiritual" merely if they have an interest in spiritual things. That is NOT the biblical perspective. Only those who hear God's voice and obey it are spiritual. Read James 1:18-27.
Lets examine what the Bible tells us is the spiritual food for a Christian. 1 Peter 2:2 tells us, "…as new born babes, desire the pure milk of the Word, that you may grow…" As infants have a taste for their mother's milk, so we are to develop a taste and a craving for the life-giving Word of God. Growing in Christ requires that we spend time in His word.
Commentator Matthew Henry puts it like this, "A new life requires suitable food. They, being newly born (spiritually), must desire the milk of the word. Infants desire common milk, and their desires toward it are fervent and frequent."