Ali bin Abi Talib, who was one of the Companions of Prophet Muhammad and fourth caliph of the Muslims, stated: "Knowledge is a small dot, magnified by the ignorant." Meaning that in the presence of widespread ignorance, simple concepts must be expounded upon in order for some to understand. In recent years science has discovered that human beings are "hard-wired" from birth to believe in the existence of a higher power, something which was discussed in Islam centuries earlier. Prophet Muhammad said that every child is born upon a natural disposition towards belief in one God, but that it is external influences (family, society, etc.) that alter this understanding. So when human beings deviate from such a simple and natural concept, they require textual and intellectual arguments in order to be convinced.
It's ironic that you should mention gravity, considering Isaac Newton had to defend his theories on gravity, some of which were challenged in modern times (Einstein's theory of relativity answered these objections). But when we look at Newton's beliefs we find that he believed in one God and was not a believer in the Trinity. He said about his book, Principia Mathematica: "I had an eye upon such Principles as might work with considering men for the belief of a Deity", meaning he wanted intellectual people to reflect upon the existence of God through the signs shown in physical science. He also said: "Gravity explains the motions of the planets, but it cannot explain who set the planets in motion. God governs all things and knows all that is or can be done." His statement: "Such a wonderful uniformity in the planetary system must be allowed the effect of choice" is an echo of an intellectual argument presented in the Qur'an, centuries before Newton. Newton's theories provide the basis of what is known about gravity, yet his scientific aspirations didn't deter him from his innate disposition towards believing in one God.