Life is more complex than any of us can possibly imagine. The universe itself could not have formed the way it did without certain conditions happening all at the same time. The slightest variation of any of these constants would have resulted not in a “big bang” but in a big flop.
The earth itself is the perfect size for life to exist. It is also the perfect distance from the sun. Any variation in size or distance would upset the delicate balance necessary to sustain life.
Did all of this happen by chance? Even the famous scientist Carl Sagan remarked, “The neurochemistry of the brain is astonishingly busy, the circuitry of a machine more wonderful than any devised by humans.”