The work of the church is to edify the believers with understanding of all God wants us to believe, our faith. That "Faith" deals with the content of Christian belief. It is the doctrines that make Christianity unique from all religions in the world. The highlight, of course, is the Gospel of Jesus Christ, who He is and what He has done to bring us salvation. Believers need to be well versed in Scripture, and the reason for that comes shortly in this letter.
This edification also deals with the intimate and personal knowledge of God so that a believer can rest in their relationship with Him through Jesus Christ. This is a truth that needs to be taught and understood more and more in our daily lives. Enjoying a personal relationship with God is what makes Christianity stand out from all other religions. Our God is personal and enjoys seeing us grow in our intimacy with Him.
The end result of this work: that we would mature in our lives to measure up to Christ, Himself. This is what the Spirit of God seeks to do with every believer. Read Romans 8:29 where we are told that God's purpose is to "conform us to the likeness of His Son."