I entirely agree with you, my friend, that the gross Calvinistic notion of original sin, is as injurious to the perfections of the Divine Being, as shocking to reason: yet I think it cannot be denied that bad example, and hereditary physical causes may have some effect upon the moral character; and these in a measure, from the earliest ages (or if you please from Adam himself) may have affected posterity. But as a constitutional disease may by proper precautions and remedies be much meliorated, if not entirely eradicated; so the disorders of the mind, by early good habits, care and attention, may in a similar manner be softened, or rectified. This conviction should incite us to watchfulness and diligence, to “work out our salvation with fear and trembling.”
Human nature has been much calumniated, and the calumny glances at the Being who produced it. Is it possible to imagine  that Infinite purity could implant in the creatures of his power, a natural propensity to evil, and mischief? The very idea is blasphemous: on the contrary, the whole structure of mind and body disposes to virtue, since every deviation from it involves the criminal in misery and disorder. We are hastily led to conclude that vice predominates in society, because it is more obvious and glaring; and few comparatively, have either capacity, leisure, or opportunity to mark the nicer shades and discriminations of character. We are struck with the fact, but perceive not the chain of gradations, and motives that led to it; nor the virtues that are sometimes engrafted on the ruling passions.
“What crops of wit, and honestly appear,
From spleen, from obstinacy, hate, or fear.”
“The thread of our life is of a mingled yarn.” Nature seldom produces either heroes, or monsters; there are none so perfect, as to be free from some darker tints; nor any so vile, as to deserve unmixed abhorrence: actions which at first view fill us  with admiration, or with horror, when analyzed more accurately, will admit of many deductions and extenuations. Our virtues and our vices border on each other: nice is the boundary that separates them. The same energy, called forth by different circumstances and associations, may give rise to heroic virtue, or daring outrages: great talents have alternately been the blessings, and the scourges of society. The inconsistencies, and the inequalities of superior characters may perhaps bring them nearer to a level with common minds, than is generally imagined. We are all the children of one Parent, who regards his moral offspring with a more equal eye, than a superficial observer at one hasty glance might conclude. Not that I would be understood to confound all distinctions betwixt virtue and vice; there are undoubtedly many gradations between a Socrates, and Anytus, who by false accusations deprived the world of its then greatest ornament. Yet they both acted under the general plan of Providence, which finally must intend, not merely the good of the whole, but of each individual;  though a far greater degree of punishment will be necessary for the rectification of a greater degree of turpitude.
The first and noblest characters that have adorned humanity, have generally arisen out of severe trials, and adverse circumstances.
“So many great
Illustrious spirits, have been conversed with woe;
Have in her school been taught; as are enough
To consecrate distress.”
The gospel also teacheth that “whom the Almighty loveth, he chasteneth.” May we not conclude from hence, that as gold is tried in the fire, so the human character is perfected by sufferings; and those from whom the dross is separated in this first stage of existence, are assuredly nearer to the state of pure and perfect enjoyment, where out faculties will be no longer enigmatical; and where these glorious capacities, here too frequently only inlets to pain, will find their proper gratification? Whether we reason from experience, observation, or analogy,  every conclusion goes to prove, that this world is a state of discipline and progression, and can never be
“The final issue of the works of God,
For ever rising with the rising mind.”
I am, &c.