We hear it everywhere: service, not theology, is the heart of the Christian religion. Pastors, conference speakers, writers, professors, and teachers tell us that if we aren't serving our communities or bringing clean water to African villages we aren't really Christian, we don't understand the faith.

But is that true? Are we really to believe that our profession of faith is best served by fulfilling the physical needs of others, rather than learning about God and teaching what we learn? Or have all these voices been shaped primarily by a culture that doesn't believe in an eternal soul and looks only to temporal needs and desires?

In the Sermon on the Mount, Jesus summed up His teaching on worry and physical provision by saying, "Seek first the kingdom of God and his righteousness, and all these things will be added to you." On the surface, it seems that Jesus is telling us not to worry about our physical circumstances, but to focus on knowing God and seeking to serve Him.

The majority of today's church leaders, however, have been influenced by postmodernism, so for them these words can't just mean what they mean on the surface—they have to be deconstructed and mined for their deeper significance. Usually they focus on the phrase "kingdom of God" and try to invest it with some kind of extrabiblical meaning.

"Kingdom of God," it is supposed, refers to creation, or the world, or simply to other people (the "brotherhood of man"), so that seeking the kingdom of God is shorthand for looking to fill the needs of others. Never mind that the kingdom of God refers to the people of God, the Church, and that seeking God's kingdom is meant to signify seeking Him.

Our Christian faith is centered entirely on God. The Gospel is that God, who created all things, gave Himself as the perfect sacrifice for our sins; that sin entered the world through our first father, Adam; that Jesus Christ, God in human flesh, lived sinlessly and died perfectly on our behalf; that those who have faith in Him through the Holy Spirit will live forever with Him in the new earth.

Paul expresses this beautifully in 1 Corinthians 15:1-11. Unlike contemporary teachers, however, he reiterates again and again that each aspect of the Gospel transpired in fulfillment of the Scripture, thus establishing God's written Word as the final authority for all our knowledge about Him.

This is a far cry from what we hear today. Instead of God, the center of our faith is ourselves; instead of His work, we focus on our own work; instead of the Bible, our authority is subjective experience and feeling. As a result, those who adhere to this false faith claim that doctrine and knowledge of God are not as important as service to others, or that they aren't important at all.

It is essential that Christians reclaim the centrality of doctrine. We are shaped not by our deeds, but by our understanding; our good deeds flow out of our increased understanding of God's character and work as described in the Bible. We've selected the books in this section for their biblical faithfulness, doctrinal purity, and helpfulness.

The study of the doctrine of God is known as theology proper, and includes the doctrines of God the Father, God the Son, God the Holy Spirit, and the Trinity. Jesus Christ himself believed the whole Bible to be a testimony to Himself (Luke 24:13-27); if we affirm Christ as Lord, how can we neglect to search for Him throughout the very Word He has given us?