I have always been intrigued by the scientific types who refuse to believe in God. That said, it is important to concede that it is hard to believe in something that you cannot directly see or measure, but can only detect by its effects. (Kind of like atoms.) Additionally, it should be noted that in scientific theory, a fact is anything that can be disproved. If it cannot be disproved, it is an article of faith. (Is the belief in the non existence of God likewise an article of faith?)
As we examine the Universe, we discover that basically everything is governed by physics. Physics is logical. The first rules of physics are fairly easy to understand. Among these first rules are: Two objects can't share the same space at the same time. An object at rest "desires" to stay at rest; an object in motion "desires" to stay in motion. You cannot create something from nothing. When matter changes to energy, and energy into matter, there is loss. (This is pre Einstein physics. Post Einstein theories make things too complicated for a short article.)
Lets examine the principal that you cannot create something from nothing and that when energy or matter change from one to the other there is loss.
We have all heard that all energy on earth comes from the Sun. Nuclear energy, electrons and subatomic particles from the sun, is captured by plants which help them grow. The plant does not consume or store all of the solar energy it takes in. Animals eat the plants. Animals get energy from the plant, which got energy from the sun, but do not get as much of the sun's energy as the plant received. Eventually, these plants and animals form hydrocarbons like coal and oil. Coal and oil are burned to heat water, to make steam, to turn a turbine, which spins a magnet, which moves electrons and subatomic particles along a wire. At each step, less and less energy is transmitted.
To express this in a more fundamental way, when something is given away, the less of it you have to give. I only know of one exception to this fundamental rule. Love. The more love a person gives away, the more love they have within them to give away. Anyone who has taken a new child or grandchild into their heart has experienced this.
Love is the only thing of which I am aware that defies these universal rules of physics. I am not aware of any correlation with the amount of love a person receives with their ability to give it. The more love a person gives, the more they have to give, even if it is not well received.
After most of a lifetime of active theological study I have encountered many proofs of God and analyses which point out the errors of each. It seems to be an inherent aspect of our relationship with God that you must have faith to know him. It seems that God declines to be conclusively proven. Yet, the most important and consistent revelation in the New Testament is God's love.
For me, the fact that love appears to be the only thing which defies the known laws of the known universe helps prove to me that God exists and that he loves his creation.