For convincing a man of sin by the law, consider Jer. 17.9,10
"The heart is deceitful above all things, and desperately wicked: who can know it? I the Lord search the heart, I try the reins, even to give every man according to his ways, and according to the fruit of his doings."
Here the Lord teaches two things:
1a) That the fountain of all our wickedness, and actual sinning against God, is in the heart, which comprehends the mind, will, affections, and all the powers of the soul, as they are corrupted and defiled with original sin;
the mind being not only ignorant and incapable of saving truth, but also full of error and enmity against God; and the will and affections being obstinately disobedient to all God's directions, and bend toward that only which is evil: "The heart" (saith he) "is deceitful above all things, and desperately wicked;" yea and unsearchably wicked, so that no man can know it; and Gen 6.5 "Every imagination of the thoughts "of man's heart is only evil continually," saith the Lord, whose testimony we must trust in this and all other matters;
and experience also may teach us, that, till God make us deny ourselves, we never look to God in anything, but fleshly self interest alone does rule us, and move all the wheels of our actions.
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