Concerning God we must think spiritual, for the bible says, "God is spirit," (John 4:24 NASB). So think spiritual!
Let's first deal with the skeptic and his argument, "I cannot see God, therefore He cannot exist." This argument is based on the premise, that if you cannot see or touch something with the physical senses, it cannot exist. Let's see if this premise is true.
1. Do you see love; the kind of love that Christ expressed? Can you reach out your hand and touch it? You may see the effects of love, but you do not see love. There are some people that do not love because they do not have faith in it. Those that practice love, believe in it. Love is a spiritual characteristic or attribute. You cannot see nor touch it. You may hear about it. You may feel or see the effects concerning it, but you do not see nor can you touch love itself. It is understood by faith. John 3:16 says, "For God so loved the world that He gave His only begotten Son . . ." In Romans 5:6-8, the bible teaches that God demonstrated His love to mankind by sending Jesus to die for sinners. This is not comprehended through the physical senses, it is understood by faith.
2. Do you see reason, a product of the mind? You may see a brain, but you don't see reason nor can you touch it. Who would deny that it exists?
3. When a person dies, you see the same physical form of the body, though something is missing. For humankind, the bible calls it the spirit; "the body without the spirit is dead," (James 2:26. NASB) Some call it life; however, it exists. You cannot see nor touch it with the physical senses.
These three arguments that we've discussed are not physical traits, but are spiritual in nature and not understood through the physical senses. They are understood by faith, notwithstanding faith comes by hearing. Even those things that we see physically, by faith we understand their origins. "By faith we understand that the worlds were prepared by the word of God, so that what is seen was not made out of things which are visible." (Heb. 11:3 NASB)
4. One more argument that I would make, is that of magnetism found in the physical world. Who would deny the existence of this phenomena? You may see the effects of magnetism, or feel its force through a medium; such as holding and moving a magnet against steel, but you do not see nor feel magnetism itself.
So much for the premise that "if you cannot see or touch something with the physical senses, it cannot exist." This is a false premise.
In 1 Cor. 5:7, the bible says, "For we walk by faith, not by sight." (NASB). Whether or not God exists, is a matter of faith, and not of carnal senses. Faith is believing in things you are convinced exists though you cannot see them. It also includes that you are assured of those things you hope for, though you do not see them. Hebrews 11:1 states, "Now faith is the assurance of things hope for, the conviction of things not seen." Romans 10:17 states, "So faith comes from hearing and hearing by the word of Christ." From these passages we conclude that if we are to have faith in the existence of God, we have to hear what he has to say. We find out what He says by reading the scriptures, "All scripture is inspired by God . . ." (2 Timothy 3:16. NAS). The scriptures are a testimony and evidence concerning the existence of God.
In the bible there are over 3,500 references to the word "God." This does not include the references to Him when He is referred to as "Lord." There were about 40 different writers of the bible. What is so significant about this is that when reference to God is mentioned in their writings, the writers do not contradict one another in what they have to say concerning Him. The only way this could have come about is that these writers had to be inspired by God. Inspiration by God does not simply mean to have an idea or an abstract influence about something. It means to be given words directly by God to be spoken and/or written.
Another evidence we have concerning the existence of God is prophecy. Many writers foretold of coming events hundreds of years before they actually came to pass. The writers that wrote of the fulfillment of the prophecies were very specific as to each prophecy. These events were very specific. They were not general events in which we might say, (in protest against their claimed origin), "History repeats itself." They were specific to the point that showed their divine origin. Not one or two, but hundreds of prophecies. If this does not shake your doubts, (if you have doubts), I don't know what will. I have never known anyone in my lifetime to have prophesied so specifically and it turn out like they prophesied. On the contrary, those who have prophesied specific events to come in my lifetime, have never had any fulfillment. This shows they were simply false prophets. Not so in the bible. You will never find a more reasonable and accurate recording of specific prophecies and fulfillment. This has to be significant to any reasonable mind. This great evidence shows that God was behind every prophecy in the bible. This kind of power was not in humans apart from God.
When we read God's word, we read His testimony. Evidence of His existence is revealed to us as His words of truth sink into honest hearts. Testimony and evidence concerning the existence of God is abundant in the scriptures. If you have never heard or read the scriptures, then you have never heard the testimony of God. If you have read the scriptures but did not understand what it says, then you did not understand the testimony of God. Can one justly conclude there is no God who has not read the testimony or has not understood the testimony of the bible? Would a judge or jury do justice to render a verdict toward one charged with a crime, yet not hear testimony either for or against him? Would it be just, to render a verdict, if testimony was heard but not understood? Put yourself into the defendant's chair. What kind of a judge and jury would you desire? Would you desire the prejudiced or the unprejudiced, unbiased and fair judge and jury.
The challenge for you and I is this:
1. To investigate the scriptures with an open and fair mind. Luke said in Acts 17:11, concerning the Bereans, "Now these were more noble-minded than those in Thessalonica, for they received the word with great eagerness, examining the scriptures daily, to see whether these things were so." (NASB)
2. To find out what God has planned and what is expected of us. Ephesians 5:17 says, "So then do not be foolish, but understand what the will of the Lord is." (NASB)
In conclusion, let it not be said of you nor I, "The fool has said in his heart, 'There is no God." (Psalm 14:1 NASB)