Spiritual life always needs opposition.

It flourishes most luxuriantly in adverse circumstances.

We grow best under weights.
We find our richest blessings in the burdens we dread to take up.
The word "character" in its origin is suggestive.

It is from a root which signifies to scratch, to engrave, to cut into furrows.

Then it comes to mean that which is engraved or cut on anything.