Let us think of patients who are ill with tuberculosis.

"The physicians put them out in the sunlight and fresh air, both in summer and in winter. There they lie until a cure is gradually effected by the rays of the sun. The recovery of these patients is not dependents upon their thinking, in the sense of understanding the effect of the sun's rays or how these rays work. Neither does their recovery depend upon the feelings they experience during the rest cure.
"Nor does it depend upon their wills in the sense of exerting themselves to will to become well.
On the contrary, the treatment is most successful if the patients lie very quietly and are passive, exerting neither their intellects nor their wills. It is the sun which effects the cure. All the patients need to do is to be in the sun.
"Prayer is just as simple.
"We are all saturated with the pernicious virus of sin; every one of us is a tubercular patient doomed to die! But 'the sun of righteousness with healing in its wings has arisen.' All that is required of us, if we desire to be healed both for time and for eternity, is to let the Son of righteousness reach us, and then to abide in the sunlight of His righteousness."

"Prayer" by O. Hallesby