The temperature and fluctuations of the cosmic microwave background, the cosmic redshift of supernovas, the structures found in large scale galaxy distributions and the abundance of light elements together give us enough data points to fix the age very precisely, and to be very certain that the universe was once hot and dense.
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition
