Both luxury and religiousness help to harden the heart, and they give it a peculiar callousness toward the Gospel.
The rough man who swears at and scorns God's mercy is hard in his own way. His hardness is like that of the rock that requires the blow of hammer and chisel to break in pieces.
The polished, religious man is hardened to his need of God in a different way. His heart is like a lump of India-rubber. Hit it as you will, it only flings back the stroke of the hammer.
The ancient battering ram which could crush down stone walls and iron gates was often baffled by bags of straw and sand placed in front of walls and gates.
It is this India-rubber kind of hardness, this respectable, religious-hardness of heart which is so difficult to overcome. It repels, flings back, the blows of the Gospel.
"AS MOSES LIFTED UP
THE SERPENT IN THE
WILDERNESS, EVEN SO
MUST THE SON OF MAN
BE LIFTED UP: THAT
WHOSOEVER BELIEVETH
IN HIM SHOULD NOT
PERISH, BUT HAVE
ETERNAL LIFE.”