Let none despise the strivings of the Spirit in the hearts of the young; let not boyish anxieties and juvenile repentances be lightly regarded. He incurs a fearful amount of guilt who in the least promotes the aim of the Evil One by trampling upon a tender conscience in a child. No one knows the age of the youngest child in hell; and therefore none can guess at what age children become capable of conversion. We at least can bear our testimony to the fact that grace operates on some minds at a period almost too early for recollection. Nor let it be imagined that the feelings of the young are slight and superficial—they are frequently of the deepest character. The early woundings of the Saviour are made upon hearts not yet rendered callous by worldliness and sensuality. The Christian whose lot it was to be smitten in his childhood, will well remember the deep searchings of heart and the keen convictions of soul which he endured.
O beloved, how much have we to bless our Jesus for, and how much for which to reprove ourselves! Did we not stifle our conscience, and silence the voice of reproof? Were we not deaf to the warning voice of our glorious Jesus? When he smote us sorely, we returned not to kiss his rod, but were as refractory as the bullock unaccustomed to the yoke. Our most solemn vows were only made to be broken; our earnest prayers ceased when the outward pressure was removed; and our partial reformations passed away like dreams of the night. Blessed be His name, he at last gave us the effectual blow of grace; but we must for ever stand in amazement at the patience which endured our obstinacy, and persevered in its design of love.
Charles Spurgeon, The Saint and His Saviour, pp 45-46