"Know the truth, and the truth will set you free."
I found an extremely interesting opinion of what this may actually have meant among early Christian gnostics that seems a show a massive change in doctrine, here being illustrated by none other than Clement of Alexandria. The "truth", according to his description of the mysteries that lay at the heart of religious thought itself "was arrived at through the understanding of nature using reason." This stands in complete contrast to the way modern Christian fundamentalists look at evolution and other sciences
"When we have fully realized our plans with respect to these notes [i.e., the Stromateis], in which, if the spirit wills, we will attend to the pressing need—for indeed it is vital, before coming to the truth, to lay out that which must be said as preamble—we shall move on to the true gnostic science of nature [γνωστικὴ φυσιολογία],16 having been initiated into the lesser mysteries before the great [τὰ μικρὰ πρὸ τῶν μεγάλων μυηθέντες μυστηρίων], so that nothing will be in the way of the true revelation of divine mysteries [ἱεροφαντίᾳ], our having completed the preliminary purifications and explanations of the things needing to be passed on and communicated."
Thus, the science of nature according to the canon of the truth of the gnostic tradition, which is to say, the epopteia, begins with cosmogony and ascends from there to the department of theology [τὸ θεολογικὸν εἶδος].
"Accordingly, we shall make the book Genesis written by the prophet our starting point for this account of the tradition, exposing in due course the doctrines of the heterodox and endeavoring as much as possible to refute them. But all of that will be written according to divine will and inspiration. For the time being, it is necessary to turn to the subject at hand and to finish the account of ethics". (Strom.22.214.171.124–4)
This passage distinguishes the great mysteries from preliminary matters of instruction in ethics, called the lesser mysteries. The greater mysteries involve the rational study of nature, which is founded on cosmogony and culminates in theology. The result of this study is epopteia, the name given to the highest degree of revelation experienced by initiates in the Eleusinian mysteries.
In short, spending the day in Church having the world divided into "good and evil" "right and wrong" is the lesser concept of religious inquiry or theological training and thought. Science, a thorough understanding of the natural world arrived at through reason...not faith! --- is a the way to understanding the Truth, and natural history is the way through which one arrives at theological Truth.
It appears quite clear from this that somehow the Church teachings that came later from Rome must have twisted the meaning of the words, perhaps so as to not be guilty of changing the Gospels literal words, but by changing the "Words" definitions.