Nature, as an aspect of the doctrine of creation, is discussed in more detail in the dilogic on creation and providence. There, nature is recognized as the realm of "second causes" -- a term originated by Descartes in the 17th century. But here, the issues are the relation between knowledge derived from nature and knowledge derived from scripture, and whether nature is a legitimate source of knowledge for a Christian.
Truth, in its fullest sense, has three features: meaning, objectivity, and unity. Meaning is the sense of truth that Christ proffers in scripture: "I am the bread of life. He who comes to me will never go hungry, and he who believes in me will never thirst." (John 6:35). "For this reason I was born, and for this I came into the world, to testify to the truth. Everyone on the side of truth listens to me." (John 18:37b). "I am the way, and the truth, and the life." (John 14:6a). "If you continue in my word, you will be my disciples indeed, and you shall know the truth, and the truth will set you free." (John 8:31-32).
Objectivity is the sense of truth that is the goal of science. Science attempts to gain knowledge by careful observations and experiments. These can (at least in principle) be repeated by anyone, anytime. Even though objectivity is a legitimate goal, this does not mean that all knowledge must be objective in order to be true -- that is positivism (see the dilogic on Epistemology).
Unity ties together meaning and objectivity. It says that there is ultimately one truth, not two. Dualism -- the view that knowledge is split into two (or more) incompatible realms -- is rejected by theists, since they affirm that God revealed both nature and scripture; hence they have a unified origin. (On the other hand, this unity is not intended to deny the view that truth is constituted on many levels of meaning, or levels of reality. All creation has aspects of both unity and diversity; see the dilogic on the Trinity.)
God not only created the universe, but "God saw all that he had made, and it was very good." Hence our attitude toward science -- seen as the exploration of God's creation -- should be free and enthusiastic.
"Some are weakly afraid lest a deeper search into nature should transgress the permitted limits of sober-mindedness; wrongfully wresting and transferring what is said in holy writ against those who pry into sacred mysteries, to the hidden things of nature, which are barred by no prohibition....
"But if the matter be truly considered, natural philosophy [science] is after the word of God at once the surest medicine against superstition, and the most approved nourishment for faith, and therefore [science] is rightly given to religion as her most faithful handmaid, since the one displays the will of God, the other his power. For he did not err who said, "Ye err in that ye know not the Scriptures and the power of God" [Mark 12:24], thus coupling and blending in an indissoluble bond information concerning his will and meditation concerning his power."
Francis Bacon, Novum Organum,
Aphorism 89 (1620).
With such encouraging words, the modern scientific revolution was initiated.
R. C. Sproul, "Providence, Science, and the Sovereignty of God", in Perspectives on Science and Christian Faith, 41(2), June 1989."It is not idolatrous for scientists to seek a more comprehensive understanding of ordinary providence. Indeed it may reflect a very advanced form of reverence.... The Christian need not be threatened by any bona fide scientific discovery. Of all people we have an enormous investment in truth. Of course not all claims by scientists represent truth. But where truth is found and truth is published, God is honored. The secondary causes bear witness to the primary Cause. Nature bears witness to supernature. The heavens are still declaring the glory of God [Psalm 19:1]."