The Bible does teach that man is a free being, but only in terms of an absolutely free God. Man can be derivatively free as a creature precisely because God is absolutely free as the Creator. Unfortunately, many professed Calvinists are much more accomplished at affirming God's absolute freedom than man's derivative freedom. If the great error of Arminians is the notion that if man is to be free, he must be free in the sense that God is free, the error of some Calvinists is that if God is free, man cannot be free in any sense at all. But the God who created man out of his own image determined that man would be free to act within the plan of God.
Man exists in a divinely created and covenantally shaped universe.
He is, therefore, a conditioned being. But to say that man's life and his choices are not unconditioned is not to say that they are not in any sense free. Man acts according to his nature. The natural man sins because he wishes to sin. Sin is delightful to him.