God is sovereign, but He made Man a responsible being. This is a paradox. We must believe both truths for they are both taught in Scripture. Man is certainly accountable to God (Rom. 14:12; Eccl. 12:13-14). God created Adam and Eve as morally responsible persons. In fact, they were created without any sin (Eccl. 7:29). But they fell into sin (Gen. 3). Since Adam was the head of the race of humanity, and we all descended from him, his sin affected the whole human race (Rom. 5:12-19). Human nature ever since then is flawed by sin, and every human being except Jesus Christ has inherited Original Sin (Psa. 51:5; Rom. 3). As a result, we all sin by nature and by choice.

Man is born in sin with an evil and wicked nature (Eph. 2:3; Matt. 7:11). In fact, we share the same evil nature as Satan (John 8:44). We sin because it is our nature to sin. Sin completely fills every aspect of our beings from head to toe (Isa. 1:5-6). Our hearts (Eccl. 9:3) and minds are filled with sin (Tit. 1:15; Eph. 4:17-19; 1Tim. 3:8; 6:5). “The heart is more deceitful than anything else, and desperately wicked” (Jer.17:9). There is no good left in man whatsoever (Rom. 7:18). Man is basically evil, not good.

The Bible paints a grotesque picture of Man, far different than the beautiful idea Man imagines of himself. Man is dead, not sick (Eph. 2:1; Col. 2:13). He is blind, not near-sighted (2 Cor. 3:14). His heart is as hard as stone (Ezek. 11:19; Jer. 23:29). By nature we are slaves of sin (2 Pet.2:19; John 8:34; Rom. 6:16, 20) and slaves of the Devil (John 8:44; Eph. 2:2; 2 Tim. 2:26). Calvinist utterly deny that Man has a “free will.” How can it be free when Scripture so frequently says that it is a slave? Man is enslaved to his sinful nature. What’s more, he is a willing slave and does not want to be free. He would rather be a slave to sin than serve God as his king.

There’s more still. Because of the utter sinfulness of human nature, Man does not have the moral ability to change his nature (Jer. 13:23). He cannot stop sinning or even want to stop sinning (2 Pet. 2:14). Everything he does has a sinful motive behind it, even when he does what outwardly appears to be good. “The wickedness of Man was great on the Earth, and that every intent of the thoughts of his heart was only evil continually” (Gen. 6:5). Man never obeys God. He is unable any longer to truly obey God (Rom. 8:7-8; Matt. 7:18). He never seeks God (Rom. 3:11) and is unwilling to come to God for help (John 5:40). He is unwilling because he is unable (John 6:44, 65).

Calvinism also denies that Man is ever morally neutral (Matt. 6:24, 12:20). Man is always set against God. His will is not neutral or self-determining. He always wills in accordance with his nature; since his nature is evil, his thoughts and motives are always evil. But this moral inability does not annul his responsibility. Quite the contrary-it compounds his guilt. Remember, this sinfulness is self-inflicted. God does not cancel Man’s debt simply because Man has squandered the loan and is unable to pay God back. Man is guilty and deserves to go to Hell (Rom 6:23). Granted, there are degrees of sin. Some sins are worse than others, and some sinners are worse than other sinners (John 19:11). But even the least sinner is totally depraved and morally unable to obey. At heart, all men love sin and hate God with all their hearts (John 3:19-20; Prov. 21:10; Matt. 6:24). He is totally without hope (Eph. 2:12), without strength to obey (Rom. 5:6) and without excuse (Rom. 2:1).

No theology except Calvinism teaches the full truth about the sinfulness of Man.

http://www.faithbibleonline.net/biblical-calvinism-by-our-pastor-dr-curt-daniel/