1 Peter 2:1-3
2 Therefore, rid yourselves of all malice and all deceit, hypocrisy, envy, and slander of every kind. 2 Like newborn babies, crave pure spiritual milk, so that by it you may grow up in your salvation, 3 now that you have tasted that the Lord is good.
As we move to chapter 2, Peter starts with a "therefore". Why is this important? He is saying in light of what I have just said, then this. Peter is saying, since you have been chosen by God before the beginning of the world, here is how you need to grow up. First of all, He tells them what they need to get rid of. When they lived according to the sinful nature, these traits he mentions were the outcome of their way of life. Notice the lying, slander and deceit. By being born again they have the ability to rise above this condition and, live a new life empowered by the Holy Spirit.
Since they are young Christians, this isn't going to happen over night. So he uses the analogy of newborn babies craving milk. We all know what happens when a baby doesn't get fed. We will hear about it soon, even if it is the middle of the night. He uses this as a metaphor for craving spiritual milk, or being fed by God. They have tasted God is good, but know they need to continue to feed themselves. This metaphor shows the spiritual life is an ongoing process and needs continual attention. Just like we make sure we get three meals every day, we need to be fed by the Word of God, prayer and fellowship, and if possible fellowship with other believers.
When I was younger, I remember every Sunday we made sure to have dinner as a family, sometimes inviting extended family. And this is what Sunday worship is for Christians. We receive the Word, we worship, and we are fed by Holy Communion. It is family meal and we mustn't miss it.
Finally, it says we need to grow up into salvation. You may say aren't I already saved? If you believe in Jesus as your Savior, the answer is yes! We are born again and begin our life as a child of God. But this is just the beginning. Our whole lives we are growing into the life God has for us. It is a process with ups and downs, and hills and valleys, but God calls us to continue to feed ourselves and grow up.
Where are you at in your spiritual maturity? Where do you need to grow up? Seek spiritual food and milk so you can grow up into the man or woman of God you were created to be.