Sin is in no way the fault of our nature...

A reading from St. John Chrysostom, 5th century

"I am a victim of violence in my nature", you say. "I love Christ, yet my nature compels me to sin". If you were in fact compelled to sin, if you were the victim of violence, then you would be forgiven for it. On the other hand, if you sin through idleness, do not expect forgiveness.
But let us look at the question a moment to discover if we do commit sins by compulsion, under pressure of violence, rather than through idleness or serious negligence.
It is written: "Thou shalt not kill." But who compels you to kill? Who forces you to do it? On the contrary, you have to do violence to your own nature to kill someone. Which of us would light-heartedly cut a neighbor's throat? Who would gladly stain his hands with blood? No one. So the facts are the exact opposite of your contention. To sin, you have to force yourself.
God has given our nature the gift of mutual love as a result of which every living creature loves its own kind, every human being loves his neighbor. Do you see? Our nature predisposes us to virtue. It is the vices that are contrary to nature. If they win a victory, it is the fault of serious negligence on our part.
And adultery, what shall we say about that? What sort of necessity drives you to that?
You answer: ‘The tyranny of desire.’ Why, I ask you? Can you not have intercourse with your spouse and in this way defeat that tyranny? ‘But I am in love with someone else's spouse.’ In this case there is no compulsion. Love cannot be compelled. You do not love because you are forced to love: you love spontaneously, of your own free will. Sexual intercourse may be an irresistible need, but love is a free choice.
The conclusion is clearly apparent: virtue is consistent with our nature whereas vice is opposed to it.”

In other words, man is (1) basically or "essentially" good, (2) fully able to resist evil, and (3) capable of performing “good works.” Note: “Good Works” is a theological phrase from Scripture and Tradition which denotes works performed in faith by the Christian with the intent to glorify God and which contribute to his salvation.

These wise words of St. John are the consistent teaching of all of the Church “Fathers.” Based on my own personal study of the Fathers, I’ve concluded that for every action on our part as humans there are three motivations or directions in those actions: (1) Neutral goodness, (2) Evil intention (maliciousness), which is premeditated and against nature, and (3) Positive goodness (i.e., good actions performed with faith toward God).

Neutral goodness or neutrally good actions are the actions that all humans were designed to perform, and which reflect the image of God that exists in all human beings. They are the actions that Paul speaks about when he says, “Even when Gentiles, who do not have God's written law, instinctively follow what the law says, they show that in their hearts they know right from wrong.” Romans 2:14. These are not the “good works” that believers perform, but are nevertheless truly right and good actions. They possess merely a neutral goodness, however, which does not lead to eternal life, but nevertheless confirms the image of God in all men.

Actions that have an evil intention (maliciousness), are premeditated and against nature. They are clearly sinful, because they are done with full knowledge of God’s law, and are performed with willfulness in opposition to human nature, which is created in the image of God. “The” original sin committed by Adam was done with full knowledge of God’s restriction, fueled by the deception of Satan, and which mislead Adam into believing that if he acted contrary to his nature, he would be able to “make himself” into the fullness of God’s likeness. According to the Church Fathers, man is fully capable of resisting these impulses, and maintaining his “truly human” instincts, which are in essence “good.”

Maintaining our truly and essentially good human instincts (i.e., sinlessness) does not, however, equal salvation. This was the error of Pelagius who argued against Augustine in the early 5th century. Pelagius did not believe in the “necessity” of the Grace of God in salvation. That is why the third aspect of this triad of action motivations is absolutely necessary: Positive Goodness.

Positive goodness is that which is exhibited by a human being that is in accordance with his created image, but also has the positive intention of “faith toward God through Jesus Christ,” and which thus brings salvation. Positive goodness is when a human being recognizes that good actions are not intended to be performed for their own sake, but for the purpose of glorifying God, who is the origin and cause of true life. These actions (called Christian “good works”) reflect the person’s faith in God and toward God, and his acceptance of God’s uncreated grace* through Jesus Christ, which alone can “sanctify” those actions and thus “deify” the person performing them. They constitute the “living sacrifice” or “offering” that man is called to bring before God, and reflect the intended harmony between God and man, which was the original purpose for man’s existence in the first place. This “synergy” of activity between God and man is the essence of how God and man are intended to work together to bring about man’s “salvation” in Christ which was expressed by St. Athanasius and many of the other Church Fathers in the phrase: “God became man, so that man might become divine.”

So when asked the question, “Is man basically good?” One can answer “yes,” man is basically good, but “Without ‘faith’ it is impossible to please Him.” Hebrews 11:6. These short paragraphs are in no way intended as an exhaustive commentary on this subject, but are intended to provide a basic framework from which you may launch into further study of this topic.

* Refer to my previous paper on God’s Essence and Energies.