Before dealing with the creation of angels, we must set straight much missinformaiton found on the web posted by biblical literalists. Many believe that the Big Bang theory of creation contradicts the six days account in Gn 1.
Now, the truth discovered by Science by reason, cannot possibly contradict revelation because God is the author or both. The creation account described in Genesis is primarely concerned in telling us that God created the universe as is written: "In the beginning, when God created the heavens and the earth." (Gn 1:1) On the other hand, Science describes what really happened with a certain limit of certainty because scientific theory is always open to revision.
Some ask: What was there before the beginning of creation? The theological answer is "nothing" or that God created from no pre-exhisting matter. Science agrees with this because we cannot see beyond this point which is the beginning of space and time.
Stange as it may seem, modern science was not the first to describe the origin of the universe. Moses ben Nahman also known as Nahmanides (1194-1270 AD) was medieval Jewish scholar, Sephardic rabbi, philosopher, physician, Kabbalist and biblical commantator. He was the first to propose the "Big Bang" theory. He wrote: "At the briefest instant following creation all the matter in the universe was concentrated in a very small place, no larger than a grain of mustard. The matter at this time was so thin, so intangible, that it did not have real substance. It did have, however, a potential to gain substance and form and to becomes tangible matter. From this initial concentration of this intangibele substance in its minutelocation, expanded the universe and [as it] did so ... took on the tangible aspects of matter as we know it." (Gerald L. Schroeder, Ph.D., Genesis and the Big Bang, Bantam Books, NY, 1990, pg .64)
First of all Genesis 1 is inspired by God which means that the Holy Spirit guided the author to write what he did. This does not mean that everything in the account is revealed by God. What God revealed is primarely that he is the personal creator all things and that he made manind in his image and likenes. The author was otherwise left free to use his knowledge, imagination and skill to describe God act of creation.
Why does the author of Genesis write that God created matter first?
The author realized the self evident fact of interdependence of all creatures. Plants cound not grow without matter, nor could animal eat plants if there were none and human being live off both plant life and and animal life. The Catechism of the Catholic Church confirms this, "The hierchy of creatures is expressed by the order of the "six days", from the less perfect to the more perfect. "(Cat. of Cath. Ch. #342)
The second question that must have come to the author's mind was: Did God created all things at once or gradually? Before God created each form he wrote repeatedly, "Than God said...." (Gn. 3, 6, 9, 14, 20 and 24) He wanted to emphacize tha each creature was the work of God. Actually God created by "One Act" which unfolds in stages. The author needed a feamework to present God's work of creation and what more natural than the seven days of the week with which everyone was familiar.
In Genesis 1:2 we read that the earth was without form and darkness ruled the abyss and it was God who brought order out or chaos. The author ends each day of creation with the refrain, "Evening came, and morning followed..." (Gn. 1: 5, 8, 13, 19 and 23) Why this repetition? To the author evening and darkness symboized chaos while the light of morning reveals order. In effect he is telling us that it is God who bring order out of chaos daily. According with the laws of thermo dynamics, "The trend in the universe is tward chaos, not toward cosmos. And yet within a limited portion of the universe, highly ordered structures have appeared." (Gerald L. Schroeder, Ph.D., Genesis and the Big Bang, Bantam Books, NY, 1990, p.100)
The seventh day is special. "On the seventh day God completed the work he had been doing; he rested on the seventh day from all the work he had undertaken. God blessed the seventh day and made it holy, because on it he rested from all the work he had done in creation." (Gn 2:2-3) Does God need to rest like a limited creature? The author knew that God does not need rest. So, what is his purpose? To lead the people to rest and worship God every seventh day.