Thank you, my dear friend, for this great question, and I praise God for your very apparent concern for the lost. The short answer is that I don’t know that we can “convince” anyone of something that they simply do not care to believe.  Believing in God, at the end of the day, is a matter of faith, and we know that faith comes by hearing, and hearing by the Word of God (Romans 10:17). I will say, though, that the simple testimony of a Christian is a very powerful thing indeed. When we share with another the wonderful salvation that God has wrought in our souls, and our new life in Christ, this evidence of the existence and power of God is difficult to refute. And thus, it is not so much our job as Christians to give convincing arguments per se to another that God is real, but to boldly give testimony of our faith, and let the Holy Spirit do His work. Do not be discouraged if people do not believe you—not all will believe.  But, those who have an open heart and are called will come.  When before the Sanhedrin, Peter testified of the Lord before unbelievers, and the following was the result: “Now when they saw the boldness of Peter and John, and perceived that they were unlearned and ignorant men, they marvelled; and they took knowledge of them, that they had been with Jesus,” (Acts 4:13). Unbelievers will take note of our faith, that we “have been with Jesus”, and whether or not they come to believe by this, it is powerful and will not go unnoticed. In John 6:37, the Lord Jesus said: “All that the Father giveth Me shall come to Me; and him that cometh to Me I will in no wise cast out.” Now, Peter prayed for boldness to proclaim the Gospel in Acts 4:29-30, and thus our job is more to proclaim the truth of God’s Word.  Those who have ears to hear and eyes to see will have what they need, with the help of the Holy Spirit,  to believe.

But now, having said all this, here is a longer treatment of what I am wanting to say. I believe that the very best way to begin ministering to an unbeliever is by prayer.  1 Thessalonians 5:17 instructs us to “pray without ceasing,” and we see this call to prayer for the lost in Romans 10:1, Acts 26:18, 1 Timothy 2:1-6, and 2 Peter 3:9, and there are very many other verses as well. We must always remember that as much as you and I want a person to trust in God and be saved, God Himself loves that person more than we ever could, and it is His will that the lost come to know and believe on Him (John 3:16-17; 1 John 4:9-10). Indeed, this is precisely why judgment does not fall upon this guilty planet immediately as we read in 2 Peter 3:9, God is “…longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.”

But now, I believe that every person we encounter in this world is an individual, with their own individual experiences and perspectives, so there are probably very many factors involved in why some do not believe in God. But, there is one thing that I do believe is common to mankind in general, and that thing is a deeply seated perception in the hearts of men that there is a God. I believe that most anthropologists would agree that so far back as historical records might go, including pictographs, sculptures, and writings, it seems evident that every tribe or civilization of man has believed in some type of god or gods.  And indeed, there is much evidence to suggest that historically, man has believed there is some kind of life after death, and that there is some accountability for man’s actions in this present life. I do believe that the moral and civil laws of most early civilizations arise from this thought of there being an accountability to God after death. And as to the existence of God and an afterlife, we read in Ecclesiastes 3:11, “…Also He has put eternity in their hearts, except that no one can find out the work that God does from beginning to end,” (New King James Bible). Thus, I believe that most people, somewhere within themselves, have an inclination to believe in God, so the idea is already present in most, perhaps just waiting for something that will confirm this idea. Now, in Romans 1:19-20 we read that there is evidence all around us every day of the existence and power of God, “Because that which may be known of God is manifest in them; for God hath shewed it unto them. For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even His eternal power and Godhead; so that they are without excuse.” Thus, according to God’s Word, the existence of God has been manifested in the magnificent creation to all tribes and nations from the beginning and to this latest hour.  Psalms 19:1-7 brings out the testimony in creation of the presence and glory of God, which He has provided to all men, easily observable, and recognizable as though the very heavens were daily vocalizing the majesty of God. The final verses of this psalm bring out the other testimony of God’s existence and glory, and that is the written Word of God.  You see, God loves us all, and He has given us His Word, the Bible, because He wants us to know Him and to worship Him. I suppose that an unbeliever might say that it is fruitless to try to show that God is real by using the Bible, since the unbeliever would question the credentials of this amazing book.  But, to be sure, the Bible is not just a book, but it is actually the Word of God, and the Word of God is actually living and powerful and can speak for itself when one reads it (Hebrews 4:12). Indeed, the Word of God can, through the work of the Holy Spirit, impact a person’s mind and life to bring about faith and salvation. The Bible is truth, and thus it confirms the existence and purposes of God.

My dear friend, I guess that I cannot tell you the way to convince everyone that God is real, but I am convinced that He will in fact reveal Himself to anyone who truly seeks to know Him. Nature itself should convince anyone who has eyes to see and ears to hear that God exists.  It would be shear fantasy to believe that all of creation, with its complexities and balance, is just a happy coincidence.  And, the Bible is God’s message to mankind, where He reveals Himself and His purposes, and this Word of God is the most amazing testimony of all as to God’s existence and who He is. Thus, I would not be afraid to quote Bible passages to the skeptic, and challenge a thoughtful reading of the Word in order to note the consistency, the proofs of the veracity of the Bible such as the completed prophesies, and the eyewitness accounts of Christ Himself in the Gospels. You might consider beginning with the Gospel of John. Josh McDowell, a one-time atheist lawyer, studied the Bible critically to find any faults, and to apply legal arguments to prove the Bible as false; however, he ultimately wound up believing in God and becoming a very vocal Christian once he had studied. In any case, I would seek the opportunity to share God’s Word with others, then I would water all of this seed with your prayers; God is all about miracles, and the miracle of a changed life, perhaps your own conversion and godly walk in this world, is a miracle that many can readily observe and be touched by.  (SF)  (592.6)