Adam is the father of humanity. Like father, like son/daughter. When God created Adam He created him with a good nature. Thus Adam’s human-nature was totally good-natured. Therefore the nature of all humans as originally created was good.
Eve, whom God has formed in a clone-like manner from one of Adam’s ribs, shared the same good nature as original humanity. However, Eve was deceived somehow by the suggestions of the evil one and thus encouraged Adam to rebel against God. Adam consciously complied with Satan’s way of thinking and united with him against God. Thus humanity sought to be our own independent interpreter of realty autonomous from God. Thus Adam’s nature changed. He (and all his posterity including you and me) switched from being good-natured to being evil or bad-natured. However, the residue of Adam’s pre-Fall nature remains with every human being.
When God by His grace converts a human He grants that human being a new nature. In other words God restores that human being’s nature to what it was before Adam rebelled. Thus the bad-natured human being becomes a good-natured human being again. However, the residue of his/her bad-nature remains with him/her.
Whereas non-Christians are bad-natured there still remain remnants of the pre-Fall good-nature or Adamic-nature, Christians are good-natured but there are still remains remnants of their fallen nature. Thus whether non-Christian or Christian every human being has two natures: Adamic and fallen.
Because of the Adamic-nature’s connection to God the non-Christian, ever striving to remain autonomous from Him, works hard to keep on suppressing their pre-Fall-nature. Satan gleefully assists them in this endeavour by helping to dress-up darkness as light. And because of its connection to sin, evil and Satan the Christian strives to suppress his/her fallen or old nature.
Christian Apologetics is about the Christian giving the non-Christian the reason for their hope in God. When a Christian talks about God to the non-Christian in this manner he/she is appealing to the Adamic-nature of the non-Christian. However, meanwhile the non-Christian in order to remain autonomous tries hard to keep a lid on his/her innate and inherent knowledge of God by attacking and or rebutting the Christian’s verbal advances.
The Christian always has the upper hand in any (verbal) duel with a non-Christian because, though he/she tries hard to deny it, and because of his/her Adamic or old-nature, the non-Christian “knows” the Christian is telling the truth. The non-Christian, rather than give up his or her autonomy, would rather lie to himself or herself. Satan “the father of lies” gleefully assists the non-Christian with this line of defence.
But God knows His own! Therefore, resistance is useless if you belong to God and not Satan! Therefore the non-Christian will lay down his/her arms and beat his/her war-sword into a farming-implement when in time God renews His adopted child’s nature. In a reversal of what happened when Adam rebelled against God in the Garden the old will become the new and the new will become the old.
Dear reader, of which nature are you? Why kick against the goads?