Many atheists and skeptics argue that there just is not enough (or any) evidence for the existence of God. Christopher Hitchens (R.I.P.), a well-known atheist, has said, “[E]xceptional claims demand exceptional evidence” and “That which can be asserted without evidence, can be dismissed without evidence” . It is clear that atheists deny that there is evidence for the reality of God.
What does the Bible say about this? The Bible teaches that everyone in the world receives the knowledge that God exists. There should be no doubt, for those of us who take the Bible to be God’s Word, that God made it unavoidable that everyone know of His existence. Let us examine the biblical message.
God reveals Himself through nature
The Bible tells us that, “The heavens declare the glory of God, and the sky above proclaims his handiwork” (Psalm 19:1 ESV). Simply by taking the time to closely scrutinize the natural world around us, we can see the handiwork that points to an incredibly intelligent source. One would have to be willfully ignorant to attribute all the intricacies found in nature to random chance. Nevertheless, because so many generations have been indoctrinated into the false religion of ‘evolution ’, it is a common occurrence for men and women to completely miss what should be wondrous and awe-inspiring beauty, and to attribute all of creation to mindless and impersonal physical forces.
The apostle Paul writes that an attitude of denial is not normal, “For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse” (Romans 1:19-20 ESV). God’s self-revelation, visible in what He has made, makes ones rejection of Him inexcusable. A close look at nature reveals an intricate level of design that points undeniably to a Designer. Nevertheless, some still live in denial.
The Holy Spirit is working with the people of the world
God did not leave us to wander alone, aimlessly hoping that somehow we would stumble across the truth, which He intends for us to recognize. God wants us to find Him; therefore, He reaches out to us. The Holy Spirit is even now touching the hearts of people so that they might realize their sinful condition, the inevitable coming judgment, and their need of a Savior.
Jesus told His disciples that the Holy Spirit would come, “And when he comes, he will convict the world concerning sin and righteousness and judgment: concerning sin, because they do not believe in me; concerning righteousness, because I go to the Father, and you will see me no longer; concerning judgment, because the ruler of this world is judged” (John 16:8-11 ESV). The Spirit works on the conscience of every individual; making it clear to each person that there is such a thing as sin, that we are responsible to a Creator, and that we will be judged someday.
The apostle Paul, writing to the church in Rome, makes it clear that this truth is implanted even in those who have no personal saving relationship with God, “For when Gentiles, who do not have the law, by nature do what the law requires, they are a law to themselves, even though they do not have the law. They show that the work of the law is written on their hearts, while their conscience also bears witness” (Romans 2:14-15 ESV). In this passage, Paul considered there to be two groups of people; those who followed God and those who did not, those who did not were called Gentiles. Nevertheless, even these Gentiles had the knowledge of God’s existence  written on their hearts.
God’s grace enlightens every person with the Truth
The first chapter of the Gospel of John tells the reader a few things about Jesus; such as, He is eternal and He created all things. Then John tells us that, “In [Jesus] was life, and the life was the light of men” (John 1:4 ESV). However, God’s grace and mercy did not end there. He made sure that everyone was aware of his or her need for this salvation. “The true light, which gives light to everyone, was coming into the world” (John 1:9 ESV). Every person who comes into the world, at some point in his or her life, has enough knowledge of the truth of God to be saved. No one can truthfully say he or she is ignorant of the fact that God exists and that we are responsible to Him. Everyone will experience a time in their life when they know they need God. What they do with that knowledge determines their eternal destiny and destination. They make a choice to either follow and obey God, or ignore His lordship in rebellion against Him. Everyone, at some point in one’s life, must make this choice.
Responding to this universal knowledge
Jesus said, “…I am the way, and the truth, and the life. No one comes to the Father except through me” (John 14:6 ESV). He was saying that He was going to provide the way for humanity to be forgiven of their sins. He was saying that everything about Him was truth and that, “…to all who did receive him, who believed in his name, he gave the right to become children of God” (John 1:12 ESV). Jesus Himself claimed, “I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life” (John 8:12 ESV). In summary, the biblical record testifies that humanity must have Jesus, the Light of the World, or else we remain separated from God and destined to endure an eternity of punishment (Matthew 25:46). Jesus gave his life in order to pay for our sins. There is no other way to be forgiven and have eternal life. How one responds to the knowledge he or she has determines what kind of a relationship he or she will have with God. Following Jesus results in eternal life, forgiveness of sin, and an eternity in the presence of the Great Creator. Rejecting God results in a life lived out of sync with reality, increasing in sin that God will eventually judge, and heading for an eternity of punishment  (Matthew 25:46).
Atheists and skeptics know the truth, completely or in part, of the existence of God. So, what explains their atheism? Either they acknowledge the reality of God and refuse to worship Him, or they have disbelieved for so long that their consciences have become dull and they no longer feel the guilt of their sin or the conviction of the truth of God, “The fool says in his heart, ‘There is no God’” (Psalm 14:1; 53:1 ESV).
Knowing that even the most ardent atheists actually know there is a God, even though they are willfully choosing not to acknowledge this truth, should give the witnessing Christian great confidence. Armed with the knowledge that the unbeliever knows the truth, that the Holy Spirit is speaking to his or her heart, and that God is active in the witnessing process, should encourage all believers to be bold in their witness for Jesus.
Atheists may not believe in God, but, according to His Word, they cannot say they never knew that they should.
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Resources – The Holy Bible, English Standard Version “Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), copyright © 2001 by Crossway, a publishing ministry of Good News Publishers. Used by permission. All rights reserved.”  http:// www. goodreads. com/author/quotes/3956.Christopher_Hitchens