The Danger and Nature of Heresy by Obadiah Sedgwick

Of the Danger of Heresies:
1) The Scriptures charge sin, perniciousness, and damnation upon them. Paul reckons them among those works of the flesh which shut persons out of the Kingdom of God (Galatians 5:20-21). Peter calls them pernicious and damnable, and such as bring swift destruction; and, speaking of the authors of them, he says that their damnation slumbers not (2 Peter 2:1-3).
2) Heresies are compared in Scripture sometimes to gangrene or canker, 2 Timothy 2:17, “Their word will eat as doth a canker.” The canker is an invading ulcer, creeping from joint to joint, corrupting one part after another till, at length, it eats out the very heart and life.
3) Jesus Christ and His apostles give special charges and caveats against them, to take heed and beware of them, which they never would have done had they not been dangerous. Mark 8:15, “Beware of the leaven of the Pharisees.” Matthew 7:15, “Beware of False Prophets.” Philippians 3:2, “Beware of dogs, beware of evil workers, beware of the concision.” 2 Peter 3:17, “Beware, lest ye also, being led away with the error of the wicked, fall from your own steadfastness.”

The Greatness of the Danger of Heresies: Every heretical opinion buys a soul or stabs a soul. Its stabs the soul of him who maintains it, and still trades it on to murder more souls. Heresy turns the glory of God into a lie. O sirs, what is God without truth? And what is all the goodness of the Gospel without truth? And what is the fabric of man’s salvation without truth? Truth is, as it were, the pin, the clasp, the knot that ties all. And a church is never more close to dying when it gives up the truth. Heresy is like the circles in a pond; one begets another, the smaller to the greater. So one heresy begets another, a lesser to a greater.

10 chief heresies:
1) The Scriptures of the Old and New Testament do not bind us Christians.
2) That God never loved one man more than another before the world, and that all the decrees are conditional.
3) That there is no original sin.
4) That the will of man is still free
5) That the saints may fall totally and finally from grace.
6) That Christ died alike for all, yea, that his salvific virtue of His death extends to all the reprobates as well as the elect, yea, to the very devils as well as unto men.
7) That Jesus Christ came into the world not for satisfaction, but for publication; not to procure for us and to us the love of God, but only to be a glorious Publisher of the Gospel.
 That God is not displeased at all if His children sin.
9) That the doctrine of repentance is a soul destroying doctrine.
10) That the souls of men are not immortal but mortal.