Sin.

Sin no existence; nature none it hath,
Or good at all, as learned Aquinas saith.

Sin once reached up to God's eternal sphere,
And was committed, not remitted there.

Sin leads the way, but as it goes, it feels
The following plague still treading on his heels.

Sin never slew a soul unless there went
Along with it some tempting blandishment.

Sin is an act so free, that if we shall
Say 'tis not free, 'tis then no sin at all.

There is no evil that we do commit,
But hath th' extraction of some good from it:
As when we sin, God, the great Chemist, thence
Draws out th' elixir of true penitence.