Summary: God has been shouting to the Planet for centuries, but who listens? Do you listen?
1. The God Who has revealed Himself.
"The heavens declare the glory of God. The firmament shows his handiwork. Day unto day utters speech. Night unto night reveals knowledge. There is no speech nor language. Their voice is not heard. [Yet] Their sound has gone out through all the earth. And their words to the end of the world" (emphases added).
Nature doesn't say a word but it talks, and its language is powerful. It speaks of a Creator who is all powerful, beautiful, orderly, and limitless, to suggest only a little. All men are confronted with this language from their earliest years. God is speaking to them every day of His glory and artistry. Every day. The message is so powerful, says Paul, that men are without excuse! No one can say, God didn't speak to me. Sure he did. Every day of your life you could see that there must be a great God somewhere. There must be Someone in charge. Someone greater than myself. Someone to whom I must be accountable.
Unless, as David said, you are a complete fool, saying in your heart, there is no God. No, you knew there was a God but you chose to ignore His call on your life.
Here are Paul's words in Romans 1:18-25: 18For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness, 19 because what may be known of God is manifest in them, for God has shown it to them. 20For 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, 21 because, although they knew God, they did not glorify Him as God, nor were thankful, but became futile in their thoughts, and their foolish hearts were darkened. 22 Professing to be wise, they became fools, 23and changed the glory of the incorruptible God into an image made like corruptible man--and birds and four-footed animals and creeping things. 24 Therefore God also gave them up to uncleanness, in the lusts of their hearts, to dishonor their bodies among themselves, 25 who exchanged the truth of God for the lie, and worshiped and served the creature rather than the Creator, who is blessed forever. Amen.
We call this latter kind of revelation "general" revelation. But God in His mercy has also put into the world a very specific, or what we call "special" revelation. If nature were enough, we would not have to send missionaries to the unreached. They would look at a tree, or a mountain, lift their hands to God and somehow be saved. But the fact is, without special knowledge of who Jesus is [ “the way, the truth, and the life] even the majestic mountains and the beautiful flowers cannot get people into Heaven. They can only serve as invitations to seek God more. Acts 4:12 tells us there is no other name given among men whereby we must be saved, than the name Jesus. This written form of Revelation is also mentioned in Psalm 19:
7 The law of the Lord is perfect, converting the soul; The testimony of the Lord is sure, making wise the simple; 8 The statutes of the Lord are right, rejoicing the heart; The commandment of the Lord is pure, enlightening the eyes; 9 The fear of the Lord is clean, enduring forever; The judgments of the Lord are true and righteous altogether. 10 More to be desired are they than gold, Yea, than much fine gold; Sweeter also than honey and the honeycomb. 11 Moreover by them Your servant is warned, And in keeping them there is great reward.
So here is a God who speaks. He is not distant and aloof from His creation, but makes every effort to communicate to them. We start with the idea that God not only wants to speak, but has spoken.
He has spoken through nature, and through men. Look now at
1 God, who at various times and in various ways spoke in time past to the fathers by the prophets, 2 has in these last days spoken to us by His Son...
Nearly all of the Old Testament was written by prophets. Moses the prophet write the first five books. Other prophets wrote much of the other historical portions. David is called a prophet, he who wrote half of the Psalms. And from Isaiah to the end of the Old Covenant, book after book is given to us by a prophet.
There were many forms of this special communicating. Dreams and visions. Direct voices. Miracles. Sometimes God took on human form as with the visit to Abraham.