Man is a worshipping being. While human concepts of God differ, most peoples understand that there is a power or being higher than themselves. While many call themselves "atheists"--people without a deity--their godlessness is invariably linked to the traditions in which they were raised, and their denial of a God or gods is the denial of whatever their wider society worships. However, these "atheists" sooner or later deify something that a Christian would call a creature, or created thing: self, money, power, the cosmos, you name it.
However, since Adam's rebellion against God described in Genesis 3, this "God-consciousness", or natural revelation, which seems hard-wired into us is insufficient to give us a full, saving knowledge of God. As Calvin observed in Book I of his _Institutes of the Christian Religion_, this natural revelation suffices only to tell us that we are lost. And since God is infinite, eternal, and unchangeable while man is finite, mortal, and conditioned, God cannot be "discoverec" by human effort. If God is to be known to us, he must reveal himself.
The Bible is the book of God's revealing of himself to men. It deals with God's choice of the family of Abraham as his vehicle of revelation and salvation, recounts the history of that family becoming a nation, and records Moses the lawgiver and the various prophetes who came to the people of Israel. It goes on to show how promises of the Messiah are fulfilled in Jesus Christ.
The Bible is both necessary and sufficient for saving knowledge of God. In times past, prophets were sent to ancient Israel from time to time. God might show miracles, too--although biblical miracles tend to cluster around the Exodus from Egypt, entry into the Land of Canaan, the ministries of Elijah and Elisha, and int the work of Jesus Christ and his apostles. However, the coming of Christ and his working salvation for us completes the work of revelation. Thus, while the Old Testament came from various God-guided men working over a span of time ranging
roughly from 1400-400 B.C. (Moses-Malachi), the New Testament was composed by Jesus' apostles and their associates within a generation.
Hence, all of our "God Talk" must ultimately be based in the Scriptures of the Old and New Testaments. The Westminster divines meeting in London between 1645-48 spoke of how only the words of Scripture and what could be derived therefrom by "good and necessary consequence" could bind the consciences of Christians. This is the essence of Protestant Christian theologizing.
In the Roman and Eastern traditions, the traditions of the church are taken as revelation as well, for it is held that God the Holy Spirit is ever guiding his church. To this, the Protestants add that the church can and does err, and that the Holy Spirit will convince us of the words God himself has given. Scripture is therefore a check on the exuberence (sometimes sinful) of the church and a corrective. Perhaps this is why the biblically-informed Western world has long been the most actively self-critical of the world's major civilizations.
Many faiths describe themselves as "searches" for truth. Yet Christian theology is based on the premise that the truth came and found out men. More will be said later.