My principal problem is the born-again concept of an all-forgiving, all-powerful God who will wash away our sins and problems as soon as we accept Him into our lives. A comforting thought, to be sure; believe in Me, and you shall live forever, in peace and harmony. I shall comfort you, care for you, give you strength, aid you through your struggles and your follies, and all that you have done before coming to Me will be forgotten.
Unfortunately, I fundamentally disagree with this view. Men are frail beasts, prone to sin and evil, but we are also also intelligent beings with free will. If we wish to have free will, we must accept the responsibility that comes with free will. When we sin, we are responsible for that choice, or the lack of a choice. Adopting a new worldview does not wash away past failings; if it shows us our past errors, we must correct them ourselves. Asking God to fix our all problems for us is like a child asking a parent to clean up their mess, but as adults, we cannot think like children. God and man best help those who help themselves.
I should offer some caveats to the above view. Accepting a new philosophy, a new faith, a new belief system does not wash away sins against other human beings or institutions: a thief is a thief, no matter how often he may be born again. To show that he has repented of his previous ways, a man must offer recompense to the people whom he has harmed in the past. However, accepting a new faith may offer a blank slate in violations of religious doctrine; God can hardly expect nonbelievers to follow His teachings before they come to believe. In short, civil and criminal crimes are unchanged when a man changes his life's philosophy; violations of religious doctrine may be ignored in the time preceding the shift.
Another issue that I have with this worldview is the black-and-white shades in which it paints the world. Perhaps I'm playing the devil's advocate here, but I would claim that night and day are not foes, but friends. Life needs the balance of light and dark, wind and water, earth and fire, day and night, yin and yang. Shadows cannot be cast without light; light cannot shine save in the darkness. Charity helps the poor and is rightly praised, but without ambition the world would remain in paleolithic times. The challenge is not to eliminate one in favor of the other, but to find balance. Man is flawed, and will remain so; we may not celebrate these flaws, but we should not deny them.
