Man's will is free, if by free we mean it is not bound by the principle of sufficient reason, that is, it is not bound naturistically by prior causes.

God allows this freedom in man to act as his agent in creation. Understanding the laws of nature and principles of action, man works to bring about God's glory in the world. To bring the world closer to God's purpose for it.

Freedom comes at a cost. For every step in God's will, towards God's ends, man takes steps against his will, towards man's own ends.

In his impatience, man takes steps to pull the perfected glory of God closer to him in time. This haste to bring about the glory of God on man's own timeline, which entails a haste to bring about man's own ends, is the definition of evil. This lack of patience is the cardinal sin.

Rather than endure in long-suffering, man conceives of God's will as punishment. Intent on his own ends and his own timing, man will project this perceived punishment onto others, justifying harsh treatment as God's will.

This is the great problem of self-righteousness, the great heresy, and indeed, the original sin.

(http://www.autoadmit.com/thread.php?thread_id=4853945&forum_id=2#42605112)