This is the second of two part. You can read the first part here.
Lemaitre‘s Cosmology and Stephen Gould’s NOMA
NOMA stands for Non-Overlapping Magisteria, meaning that science and religion simply should not or do not overlap. Therefore, there is only one responsible level of explanation at a given time, either the scientific one, for example, when it comes to evolution, fossils, molecular genetics, or the religious one, which helps to understand what the meaning of life is, whether there is a soul, and Heaven. (This is of course simplistic). NOMA can be criticized, just because there are overlaps, especially when it comes to us humans: just that he can think about abstract concepts such as NOMA suggests that there is something that exceeds the purely materialistic sphere of science. While Christians complain that NOMA gives science too much competence (“it is always religion that has to give way”), Atheists see in NOMA a cheap excuse to introduce a bit of religion through the back door.
While NOMA wants to achieve a mere juxtaposition, that is not one of Lemaitre’s goals. He is concerned with the clear separation of the categories “physics” (meaning all scientifically detectable things) and “meta-physics”, and both categories (or levels) must not be blurred or mixed. He is firmly anchored in the Thomistic viewpoint, which distinguishes between the first cause (God) and the second causes (the creatures in the broadest sense), which act according to their inherent (and ultimately God-given) qualities and possibilities.
Lemaitre sees both categories simultaneously present:
“Physics does not exclude Providence. Nothing happens without its order or permission, even if this gentle action is not miraculous. Evolution, whether of the universe or of the living world, could be made at random by quantum leaps or mutations. Nevertheless, this chance has, from a superior point of view, been directed towards a goal. For us Christians, it was oriented towards the appearance of life. In what was done, there was life, intelligence and life was light in man and finally in humanity by the incarnation of the Man-God: the true light that illuminated our darkness.
Chance does not exclude Providence. Perhaps chance provides the strokes mysteriously actuated by Providence.” 
God’s providential actions will not be rendered superfluous or non-existent due to scientific insights. But Providence remains often hidden to us, similarly as God Himself remains “a hidden God”
“Truly, you are a God who hides himself” (Is 45:15)
God is hidden behind and in His creation. He is a “hidden God”, transcending all our knowledge and cognition. “Truly, you are a God who hides himself“, as we read in Isaiah [Is 45:15]. We will find this term and concept often in Lemaitre’s writings. Already in 1931, Lemaitre writes:
“I think that everyone who believes in a supreme being supporting every being and every acting, believes also that God is essentially hidden and may be glad to see how present physics provides a veil hiding the creation”.