Does God really exist? This question always brings "no" and "yes" answers. And quite frankly both answers are correct in one way or the other. But I choose the latter of the two answers.
My personal take, God exists. Lets look at the forms of evidence (based on facts, judgments, logic, research, conventional wisdom or tradition, and/or intuition) that can support this statement. When you examine a computer motherboard, you would probably think that this complex mechanism was not the outcome of mere chance, that it had been designed. Look at our body composition, the millions of cells, the way our senses operate etc. Each of us has a unique and complex body system functions. So this enormously complex body mechanism must have been designed, and that designer is God and so he exists.

The main evidence about the existence of God is the paper trail of historical records written in the Torah, Bible, Koran and others that are being discovered ruins of ancient cities.  These books can be trusted as a source of accurate information, (eventhough sometimes misinterpreted). The fact is that what can be verified scientifically should be deemed accurate; such as the people and places mentioned in those documents should indicate to us that the non-scientific ethical and moral teachings also must be accurate. It is also obvious that these are unlike any other books ever written, indicating that the driving force behind it must also be unique. The Torah and Koran actually state that God directly dictated the first four scritpures to Moses. These are credible sources with similar info that state the existence of God. For example, in Colossians 1:16-17, “all things were created by him, and for him; ‘and he is before all things, and by him all things consist’,“ further proofs his existence.

Science also provides evidence support in the existence of God. In the Bible, quote “He stretcheth out the north over the empty place, and hangeth the earth upon nothing.” (Job. 26:7). This quote supports the scientific evidence that the world is not supported by pillars or strings as people during that ancient era with limited scientific knowledge mostly believed. In Leviticus 12-14, God gave some basic health, sanitation, and illness guidelines like circumcision of young males, quarantine against contagious diseases etc, which is being practiced to date.  To me this wisdom is available only with the created.

The ontological argument maintains that since the human conception of God is the highest conception humanly possible and since the highest conception humanly possible must have existence as one attribute, God must exist. God can interact with individuals to supply personally tailored evidence for His existence and activity. When we share these experiences and thoughts, then we can accept the existence of God in faith.  It’s written that God is very near, yet we cannot see Him, an evidence of His extra ordinary dimension. “And he said, Thou canst not see my face: for there shall no man see me, and live,” Exodus 33:20.

References:

"God is not the author of everything because some things are evil. We can infer that God is the author of the punishments of the wicked because those punishments benefit the wicked. Evil is matter with no form at all, and as such has no positive existence."
http://www.iep.utm.edu/g/god-west.htm

From: Oliver J. Thatcher, ed., The Library of Original Sources (Milwaukee: University Research Extension Co., 1907), Vol. V: The Early Medieval World, pp. 359-363.

Clayton, J. N. "Who Created God."
http://www.doesgodexist.org/