This advice made by the apostle Paul to Timothy springs out before our eyes because it is so applicable today as it was in those days of the beginning of Christianity. It is more than an advice: it is an essential commandment in order to maintain the integrity of the message of the Word of God.
Paul is referring here to the package of knowledge entrusted to Timothy, the sound and true doctrines of the Christian faith. "Guard" is the language which would be used to place a valuable possession in a safe, protected from thieves and robbers. Timothy accumulated this knowledge since his childhood, Paul having contributed with his own in Timothy's maturity.
Christian faith is consolidated in the Bible, the Word of God, and it has suffered challenges and opposition throughout the ages, but has maintained its integrity until our days due to the fidelity of God's servants, who have preserved it in safety against the attacks of the enemy. These attacks have been in physical form, endeavouring to prevent the distribution of the Bible, and in ideological form, fighting against what it teaches.
False knowledge, at the time of the beginning of the church, when Paul and Timothy were alive, was mostly the doctrines of the Gnostics, who claimed to have superior secret knowledge and tried to confuse the new believers with their doctrines. The equivalent of the Gnostics is still with us today and also a great quantity of other teachings foreign to the Word of God.
No doubt the greatest "knowledge" antagonic to the Gospel, and the most insidious, is what, curiously, calls itself "science". It is considered knowledge by excellence, and has been so convincing that it is taught in schools from infancy, no contradictions admitted, even the serious objections coming from the Word of God.
This false knowledge has as its basis the theories imagined by a naturalist of the 18th century called Darwin, whose name is now known the world over for having started the "evolution" theories. They are so disseminated that any person who has gone through school, even just the primary course, knows what they are about.
Some "evolutionists" have maintained that it is not possible to have knowledge without believing in the theory of evolution - that's right, it is a belief, a faith, the religion of atheism. They teach that science and modern technology require us to believe in the principles of evolution, from lifeless molecules up until man, so that they may be understood and developed. They even state that those who believe in Biblical creation are in danger of not understanding science.
This is ironical, because evolution in reality contradicts the principles of true science, which we define as the evidence and proof of the causes and effects of phenomena observed in nature. If evolution were true, the concept of science would not make sense. Only the Biblical truths of creation give reality to science.
True science presupposes that the universe is logical and orderly, and obeys mathematical laws which are consistent through time and space. Even when conditions in regions in space and at different times are very different, a uniformity will still be seen because these laws do not change arbitrarily, even if conditions and specific processes are altered. Because of these laws, scientists can often forecast, for example, the position of celestial bodies at a future date. Such previsions would be impossible if there were no consistency in the facts, which is inexplicable by evolutionism.
But who believes in creation knows that there is order in the universe because God made all things (John 1:3) and imposed order in it. The Bible teaches that Christ upholds all things by the word of His power (Hebrews 1:3), which makes it possible for all regions of the universe to work in a logical and orderly manner, as if obeying a legal system (Jeremiah 33:25) and consistent (1 Samuel 15:29, Numbers 23:19), even in very diverse physical conditions. Note: the Bible doesn't teach that the present processes are identical to those existing in the past, as 'uniformitarianism' falsely teaches.
God is not limited by time or space (2 Peter 3:8, Psalm 139), but maintains the consistency of universe for our benefit. He has guaranteed that we can count upon it (Genesis 8:22). But He is not Himself tied to His laws, as proven by the signs registered both in the Old and the New Testaments. These Christian principles are absolutely essential for true science, both in its experiments and in its previsions.
Evolutionists depend upon the Biblical principles of consistency and uniformity to develop their "science", but reject the Bible which is the source. They are inconsistent by doing this. They declare that the universe does not follow a rational plan, yet base their "science" upon consistent and uniform laws which require a rational Author. Deep inside they know of the existence of the biblical God (Romans 1:19-20), but by professing the false knowledge they have strayed concerning the faith (1 Timothy 6:21).
A Christian may use an experience of the past as guidance for what will happen in the future because, in a certain way, God has promised that the future will reflect the past (Genesis 8:22). But those who reject Genesis cannot reason what is the motive for uniformity in nature. An answer like "it has always been, so it shall ever be like this" isn't scientific, because cause and effect are missing. Also "it is natural for matter to always function in a regular way", attributing regularity as a property of universe, fails in the same way. True science requires an explanation of why regularity is a property of universe.
If evolution were true, there would be no rational reason to believe in it! If life were the result of evolution, then the brain of the evolutionist would only be the result of millions of years of accidental processes. The brain would only be a collection of chemical reactions preserved because they would have had some value for survival in the past. If evolution were true, then the thoughts of the evolutionist would be simply the result of a chemical reaction over time.
Therefore, an evolutionist must think and say that "evolution is true" not for rational reasons, but as the inevitable consequence of a blind chemistry. A really scientific analysis presupposes that human mind is not just a chemical process. Reason presupposes that we have liberty to consciously consider the various options and to choose the best. Evolutionism subverts the preliminary conditions for rational thought, so destroying even the possibility of there being knowledge and science.
Summing up, we conclude that evolution is anti-science and anti-knowledge. If evolution were true, science would be impossible because there would be no reason to accept the uniformity of nature of which all science and technology depend. There would not even be any reason to think that a rational analysis would be possible, because the thoughts of our mind would be no more than the inevitable result of irrational chemical reactions. Evolutionists can only use science and gain knowledge because they are inconsistent: saying they believe in evolution, they nevertheless accept the principles of biblical creation.