Welcome to the Church!!!
RCIA is wonderful! I met my husband thanks to a friend of mine who is a wonderful convert (she is constantly trying to learn more about our Church and knows more than a lot of cradle Catholics). I truly admire the thirst for the Truth that many converts have, an example for many of us cradle Catholics.
Are you familiar with the definition of natural law? Like Vluvski pointed out, it is not the same as the laws of nature.
Maybe this can help you (from the Catechism):
37 In the historical conditions in which he finds himself, however, man experiences many difficulties in coming to know God by the light of reason alone:
Though human reason is, strictly speaking, truly capable by its own natural power and light of attaining to a true and certain knowledge of the one personal God, who watches over and controls the world by his providence, and of the
natural law written in our hearts by the Creator; yet there are many obstacles which prevent reason from the effective and fruitful use of this inborn faculty. For the truths that concern the relations between God and man wholly transcend the visible order of things, and, if they are translated into human action and influence it, they call for self-surrender and abnegation. The human mind, in its turn, is hampered in the attaining of such truths, not only by the impact of the senses and the imagination, but also by disordered appetites which are the consequences of original sin. So it happens that men in such matters easily persuade themselves that what they would not like to be true is false or at least doubtful. 13
1952 There are different expressions of the moral law, all of them interrelated: eternal law - the source, in God, of all law; natural law; revealed law, comprising the Old Law and the New Law, or Law of the Gospel; finally, civil and ecclesiastical laws
1954 Man participates in the wisdom and goodness of the Creator who gives him mastery over his acts and the ability to govern himself with a view to the true and the good. The natural law expresses the original moral sense which enables man to discern by reason the good and the evil, the truth and the lie:
The natural law is written and engraved on the soul of each and every man, because it is human reason ordaining him to do good and forbidding him to sin . . . But this command of human reason would not have the force of law if it were not the voice and interpreter of a higher reason to which our spirit and our freedom must be submitted. 5
1955 The “divine and natural” law shows man the way to follow so as to practice the good and attain his end.
The natural law states the first and essential precepts which govern the moral life. It hinges upon the desire for God and submission to him, who is the source and judge of all that is good, as well as upon the sense that the other is one’s equal. Its principal precepts are expressed in the Decalogue. **This law is called “natural,” not in reference to the nature of irrational beings, but because reason which decrees it properly belongs to human nature: **
Where then are these rules written, if not in the book of that light we call the truth? In it is written every just law; from it the law passes into the heart of the man who does justice, not that it migrates into it, but that it places its imprint on it, like a seal on a ring that passes onto wax, without leaving the ring.
The natural law is nothing other than the light of understanding placed in us by God; through it we know what we must do and what we must avoid. God has given this light or law at the creation.
1956 The natural law, present in the heart of each man and established by reason, is universal in its precepts and its authority extends to all men. It expresses the dignity of the person and determines the basis for his fundamental rights and duties:
For there is a true law: right reason. It is in conformity with nature, is diffused among all men, and is immutable and eternal; its orders summon to duty; its prohibitions turn away from offense … To replace it with a contrary law is a sacrilege; failure to apply even one of its provisions is forbidden; no one can abrogate it entirely.
1958
The natural law is immutable and permanent throughout the variations of history; it subsists under the flux of ideas and customs and supports their progress. The rules that express it remain substantially valid. Even when it is rejected in its very principles, it cannot be destroyed or removed from the heart of man. It always rises again in the life of individuals and societies:
Theft is surely punished by your law, O Lord, and
by the law that is written in the human heart, the law that iniquity itself does not efface.
