Isaiah 53:4 cannot refer to disease of the soul.
Neither of the words translated "sickness" and
"pain" are applied to the spiritual but to the
physical.

This is proven by Matthew 8:16-17, ". . . .and
He cast out the spirits with His word, and healed
all that were sick; that it might be fulfilled which
was spoken by Esaias, the Prophet, saying,
Himself took our infirmities, and bare our
sicknesses."