If this cockatrice be not crushed in the egg! – Thomas Brooks

There is infinitely more evil in the least sin than there is in the greatest miseries and afflictions that can possibly come upon you! Yes, there is more evil in the least sin than there is in all the troubles that ever come upon the world; yes, than there is in all the miseries and torments of hell! The least sin . . .
is an offense to the great God;
is a wrong to the immortal soul;
is a breach of God’s righteous law;
cannot be washed away but by the blood of Jesus; will shut the soul out of heaven, and shut the soul up as a prisoner in hell forever and ever!

The least sin is rather to be avoided and prevented than the greatest sufferings. If this cockatrice be not crushed in the egg it will soon become a serpent!

Sin, if but thought on and pondered  will break out into action  action into custom  custom into habit and then both body and soul are lost irrecoverably to all eternity!

The least sin is very dangerous! Caesar was stabbed to death with a small needle; Herod was eaten up by small worms; Pope Adrian was choked with a gnat; a mouse is but little, yet kills an elephant if he gets up into his trunk; a scorpion is little, yet able to sting a lion to death; though the leopard be great, yet he is poisoned with a head of garlic; the least spark may consume the greatest house; the least leak will sink the greatest ship; a whole arm has been gangrened by a pick of the little finger; a little opened door may betray the greatest city; a pinch of poison diffuses itself into all parts, until it strangles the vital spirits, and turns out the soul from the body.

If the serpent can but wriggle in his tail by an evil thought, he will soon make a surprise of the soul as you see in that sad instance of Adam and Eve.