Professor Stephen M. Barr’s booklet, Science and Religion, we see how “Lucky” we must be to be alive, if there is no God who created us. The conditions that made life possible are sometimes known as “Anthropic coincidences” – here are six:
(1) If the world did not obey the principles of quantum mechanics, atoms and molecules would not be stable building blocks with well-defined properties out of which living things could be built.
(2) If the electromagnetic forces between particles were significantly stronger than they are, the electric repulsion within atomic nuclei would blow them apart, except for the nuclei of the very lightest elements.
(3) If the so-called “strong force”, which holds nuclei together, were even a small fraction weaker than it is, a crucial nucleus called deuterium could not exist, and the nuclear reactions that power the Sun and similar stars would not take place – depriving earth of the energy needed for life. Moreover, these same nuclear reactions involving deuterium are needed to initiate the chain of reactions that form all the elements of the Periodic Table (except hydrogen). Without them, the only element in nature would have been hydrogen, rather than the rich palette of elements needed for life. (Twenty-five elements are found in the human body.)
(4) Neutrons are very slightly heavier than protons. Had it been the other way around, isolated protons would be unstable and hydrogen would not exist (though other elements could). Almost all organic molecules contain hydrogen, so life would probably not exist.
(5) If the number of extended dimensions of space were greater than three, gravity would act differently and would not allow planets to orbit stars – they would either plunge into the stars or fly off into space.
(6) If a parameter called the cosmological constant were not fantastically small (about 10−120), the universe would not have lasted the billions of years needed for life to evolve, but would have collapsed or blown apart in only a tiny fraction of a second.”
These show that it is surely more probable than not, that we are here by the will of someone higher than just accident or chance.
Source: Science and Religion: The Myth of Conflict, Prof. Stephen M. Barr, CTS publications