Hebrews 6:1

Therefore let us get past the elementary stage in the teachings about the Christ, advancing on to maturity and perfection and spiritual completeness, (doing this) without laying again a foundation of repentance from dead works and of faith toward God.

We all have goals that we are working toward in our lives, and each plan requires increasing our knowledge and faith.  We can’t stay at the same level of understanding of God and go forward, and it would be like a teenager never leaving kindergarten.  As we advance with God, we can grow spiritually and mature as Christians.