How did people know about God before the Bible?

Even though people did not have the Word of God, they were not
without the ability to receive, understand and obey God before there
was a Bible as we know it. In fact, there are many areas of the world
today where Bibles are not available, yet people still can and do know
about God. The issue is one of revelation—God's revealing to man what
He wants us to know and understand about Himself. While there has not
always been a Bible, there have always been means for man to receive
and understand God's revelation. There are two categories of
revelation, general and special.

General revelation deals with that revelation from God universally to
all mankind. The external aspect of general revelation are those
things which God must be the cause or source of. Because these things
exist, God must also exist in order to have put them into existence.
Romans 1:20 tells us "For since the creation of the world His
invisible attributes are clearly seen, being understood by the things
that are made, even His eternal power and Godhead, so that they are
without excuse." So all men and women everywhere can look at the
creation and know that God exists. Psalm 19:1-4 further explains that
the creation speaks clearly of God in a language that all understand.
"There is no speech or language where their voice is not heard" (verse
3). The revelation from nature is clear. No one can excuse himself
because of ignorance. There is no alibi for the atheist, and there is
no excuse for the agnostic.

Another aspect of general revelation—that which God has revealed to
everyone—is in the existence of our conscience. This is internal.
"What may be known of God is manifest in them" (Romans 1:19). People
today, because of what they have on the inside, are conscious that God
exists. These two aspects of general revelation are clearly seen in
the countless stories of missionaries coming upon native tribes who
have never seen a Bible or heard of Jesus. Yet, when the plan of
salvation is presented to them, they know that God exists because they
see evidence of Him in nature, and they know they need a Savior
because their consciences convict them of their sin and their need of
Him.

In addition to the two parts of general revelation, there are also
methods of special revelation God uses to show mankind about Himself
and His will. Special revelation does not come to all people, but only
to certain people at a certain time. Examples from Scripture of
special revelation are the lot (Acts 1:21-26, also Proverbs 16:33);
the Urim and Thummim (a special type of lot used by the High
Priest-see Exodus 28:30, Numbers 27:21, Deuteronomy 33:8, 1 Samuel
28:6, and Ezra 2:63); dreams and visions (Genesis 20:3,6; Genesis
31:11-13, 24; Joel 2:28); Appearances of the Angel of the Lord
(Genesis 16:7-14, Exodus 3:2, 2 Samuel 24:16, Zechariah 1:12) and the
ministry of the prophets (2 Samuel 23:2, Zechariah 1:1). These
references are not an exhaustive list of every occurrence, but should
serve as good examples of this type of revelation.

The Bible as we know it is also a form of special revelation, though
it may not seem like it. It is in a category all by itself, however,
because it renders the other forms of special revelation unnecessary
for today. Even Peter, who along with John witnessed Jesus talking to
Moses and Elijah on the Mount of Transfiguration (Matthew 17; Luke 9),
declared this special experience to be inferior to the "more sure word
of prophecy, to which you would do well to take heed" (2 Peter 1:19),
by which he meant the Word of God, the Bible. That is because the
Bible is a written form of all the information God wants us to know
about Him and His plan for our lives. In fact, the Bible contains all
that is needed to be known about God in order to have a relationship
with Him.

So, before the Bible as we know it was available, God used many means
to reveal Himself and His will to mankind. It is amazing to think that
God did not use just one form, but many. It makes us thankful that God
gave us His written Word and preserved it for us today in the Bible,
so that we are not at the mercy of someone else, but can study it for
ourselves! Of course, the clearest form of revelation God used was
when He sent His Son, Jesus Christ, to take on human form and walk
this earth among us, and die for our sins in our place on the cross.
That alone spoke volumes!