From the Chapter "Entanglements"

"We dread malarial fever, and fear lest it should get hold of us and drive us out of the mission field. Should we less dread this spiritual malaria, the fever of a restless soul, which has a power, we know not how, to enervate the very fiber of our being and so unnerve us for the fight? Surely this is the most dangerous form of fever possible. A fit soul in an unfit body is doubtless uncomfortably crippled, but it is not wholly ineffective; but what is the good of a fit body with an unfit soul inside it? It may as well go home at once for all the fighting it will do on the mission battlefield.

But is there not a better way?

Searcher of spirits,
Try Thou my reins and heart;
Cleanse Thou my inward part -
Turn, overturn and turn.
Wood, hay and stubble see
Spread out before Thee;
Burn, burn.

Worker in gardens,
Dig round my hidden root,
Let branch, leaf, bud and fruit
Respond in quickened life.
Seek out the canker there -
Cut out and do not spare
Thy knife.

Savior of sinners,
Out of the depths I cry,
'Perfect me or I die -
Perfect me, patient One';
In Thy revealing light,
I stand confessed - outright,
Undone.

O to be holy!
Thou wilt not say me nay
Who movest me to pray:
'Enable to endure.'
Spiritual cleansing Fire,
Fulfill my heart's desire:
Make pure."

~ Amy Carmichael, God's Missionary, pg. 27-29