The only effectual means for reforming mankind

(Letters of John Newton)

The Gospel of Christ, the glorious Gospel of the blessed God, is the only effectual means for reforming mankind.

To the man who possesses and knows the use of this grand, this wonderful machine, if I may be allowed the comparison what is otherwise impossible becomes easy.

The Gospel removes difficulties insurmountable to human power.
It causes the blind to see,
it causes the deaf to hear;
it softens the heart of stone, and
raises the dead in trespasses and sins to a life of righteousness.

No force but that of the Gospel is sufficient . . .
  to remove the mountainous load of guilt from an awakened conscience,
  to calm the violence of tumultuous passions,
  to raise an earthly soul from groveling in the mire of sensuality or avarice to a spiritual and divine life, a life of communion with God.

No system but the Gospel can communicate motives, encouragements, and prospects, sufficient to withstand and counteract all the snares and temptations with which the spirit of this world, by its frowns or its smiles, will endeavor either to intimidate or to bribe us from the path of duty.

But the Gospel, rightly understood and cordially embraced, will inspire the slothful with energy and the fearful with courage. It will . . .
  make the miser generous,
  melt the grouch into kindness,
  tame the raging tiger in the breast, and,
  in a word, expand the narrow selfish heart and fill it with a spirit of love to God, cheerful unreserved obedience to His will, and benevolence to mankind.