Summary: The Christian possesses knowledge that is not available to outsiders. Therefore, followers of the Christ must encourage their hearts that they know Christ, that they are secure in Him and they are to honour Him.
“We know that the Son of God has come and has given us understanding, so that we may know him who is true; and we are in him who is true, in his Son Jesus Christ. He is the true God and eternal life. Little children, keep yourselves from idols.” 
“The trouble with world is not that people know too little, but that they know so many things that ain’t so.” Even among the professed people of God, much of what we profess to know “ain’t so.”  If only we would restrict ourselves to what we know to be true, our message would be so much more powerful, and our appeals to the lost would be so much more effective. I have often encouraged believers to carry their beliefs lightly on their fingertips, to be gracious when disagreeing about issues of doctrine with fellow saints. We are taught, “Live in peace with one another” [1 THESSALONIANS 3:13b ISV].
If you are a Christian, you now know many things that were once impossible to know. You know God. I don’t mean you know about God—you know God! You are on speaking terms with the Creator of all things—He calls you His child. You know His awesome power; though you may not see that power displayed in its fullness, you do witness it on a continual basis as you walk with Him and as you do His will. You know the forgiveness of sin; and you know the sorrow and pain that attends life when you stumble into sin. You know the smile of heaven; and you know the distress experienced when sin has darkened your sky. Thought we long to live perfect lives, we cannot do so at this time; nevertheless, we know the Son of God. We know He is perfect; and we know we are accepted in Him.
CEREBRATIONS ON KNOWLEDGE — Let’s take a moment to think about knowledge, especially how we acquire knowledge. In broad form, knowledge may be innate, or it may be acquired. Let’s think about what is meant when I speak of innate knowledge. Innate knowledge is knowledge that is recognised by our very existence; it is, if you will, God-given knowledge. Let’s think about innate knowledge for a moment. Perhaps the most readily recognisable form of knowledge that could be considered innate, is presented in the American Declaration of Independence. In that document, as originally penned by Thomas Jefferson, the following line was found. “We hold these truths to be sacred and undeniable, that all men are created equal and independent, that from that equal creation they derive rights inherent and unalienable, among which are the preservation of life, and liberty, and the pursuit of happiness.” Of course, the Committee of Five edited Jefferson’s initial draft to read, “We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.”
Continuing our ruminations on innate knowledge, consider that no one taught you to breathe—the regular contractions of smooth muscles controlling the diaphragm is controlled by your very existence. Peristaltic action of the gut is not something that one learns, it is innate to life itself. In significant measure, the blink reflex, the gag reflex and salivation are innate to life. Failure to exhibit these reactions likely indicate a physical deficit. Though there are undoubtedly other, and perhaps superior, examples of innate knowledge, these provide examples of muscular knowledge that are unlearned.