Vatican City, Feb 4, 2012 / 06:09 pm (CNA).- The director of the Vatican Observatory said that the Church is open to the scientific theory that the world began from a cosmic explosion billions of years ago.
“The Big Bang is not in contradiction with the faith,” Father Jose Gabriel Funes said during a Feb. 2 announcement of a Vatican exhibit that will feature photos, research tools and minerals from the Moon and Mars.
Proof of God’s Existence:
The Cosmological Argument and the Big Bang Theory
|Saint Tomas Aquinas|
Seeking the First Causes/Mover
The Philosophical Argument
A Catholic theologian and Saint named Thomas Aquinas (1225-74 CE) proposed several most influential versions of the cosmological arguments to prove the existence of God. In his Five Ways I will quote only two: First the argument from first causes He argued that every event has a cause; whatever exists is here, because something else has caused it to be here (for example, children are here because of their parents). Things cannot cause themselves to exist (for example, children cannot give birth to themselves). There cannot be a never-ending (infinite) chain of causes and that this leads us to seek the first cause of everything. 
In another version he argued that things only move because they are moved by something else, which leads us to seek the first mover of everything. The argument from motion: Things move (or become something else), because something moves them to do so. It is impossible for motion in the universe to have always been happening, so it must have begun somewhere (and somehow). There cannot be a never-ending (infinite) chain of events.
His cosmological arguments were basically intended to show the existence of a being that started everything. Someone that was itself uncaused or unmoved.
|Fr. George Lemaitre & Albert Einstein|
The Big Bang Theory: The universe had a start
Father Georges-Henri Lemaitre – a Catholic priest in 1927 explained that at the very beginning of our universe, prior to that moment there was nothing but during and after that moment there was something. This is what we called today as The Big Bang Theory.
This is the dominant and highly supported theory of the origin of the universe. In essence, this theory states that the universe began from an initial point or singularity which has expanded over billions of years to form the universe as we now know it.
(a) Evidence for the Theory
|Edwin Hubble - Hubble Telescope was named after him|
In 1929 Edwin Hubble discovered that the galaxies are moving away from us at speeds proportional to their distance – this phenomenon known as ‘Hubble’s Law’ (which is named after him). This observation supports the expansion of the universe and suggests that the universe was once compacted. 
This theory also suggests that the universe was initially EXTREMELY hot, thus we should be able to find some remnant of this heat. In 1965, Radio-astronomers Arno Penzias and Robert Wilson discovered a 2.725 degree Kelvin (-454.765 degree Fahrenheit, -270.425 degree Celsius) Cosmic Microwave Background radiation (CMB) which pervades the observable universe. This is thought to be the remnant which scientists were looking for. Penzias and Wilson shared in the 1978 Nobel Prize for Physics for their discovery. 
|Arno Penzias and Robert Wilson |
(behind them: CMB Detector)
Finally, the abundance of the "light elements" Hydrogen and Helium found in the observable universe are thought to support the Big Bang model of origins. 
Scientists are convinced that our universe began with one enormous explosion of energy and light. This was the singular start to everything that exists: the beginning of the universe, the start of space, and even the initial start of time itself.
“All the evidence we have says that the universe had a beginning.” Cosmologist Alexander Vilenkin, Tufts University, Boston (USA), January 2012
“several different models of the universe that dodge the need for a beginning while still requiring a big bang. But recent research has shot them full of holes (see page 6). It now seems certain that the universe did have a beginning.” Editorial: In the beginning , New Scientist 213(2847):3, 14 January 2012
**(see page 6) referred to Lisa Grossman: “Death of the eternal cosmos—From the cosmic egg to the infinite multiverse, every model of the universe has a beginning.” Grossman, L., Death of the eternal cosmos, New Scientist 213(2847):6–7, 14 January 2012.
It does so based on the fact that the universe had a beginning. There must, the first cause argument says, be something that caused that beginning, a first cause of the universe.
The universe consists of a series of events stretched across time in a long causal chain. Each one of these events is the cause of the event that comes after it, and the effect of the event that comes before it. The world as it is came from the world as it was, which came from the world as it was before.
If we trace this series of events back in time, then what do we find? Astrophysicist Robert Jastrow, a self-described agnostic, stated that:
"The seed of everything that has happened in the Universe was planted in that first instant; every star, every planet and every living creature in the Universe came into being as a result of events that were set in motion in the moment of the cosmic explosion...The Universe flashed into being, and we cannot find out what caused that to happen."
What existed before the Big Bang? What caused the Big Bang? Why there is something rather than nothing? Scientists have no explanation for the sudden explosion of light and matter.
This tells us that the ultimate cause of the universe must never have come into existence; the ultimate Creator must be a being that exists outside of time, an eternal being with neither beginning nor end - God is the first cause of everything, the first mover of everything: the Uncaused-cause, the Unmoved-mover.