Purity of Heart
According to Soren Kierkegaard, purity of heart is to will one thing–God. He closes his book, Purity of Heart, with a prayer. Here is part of that prayer:
Father in Heaven! What is a man without Thee!
What is all that he knows, vast accumulation though it be,
but a chipped fragment if he does not know Thee!
What is all his striving, could it even encompass the world,
but a half-finished work if he does not know Thee:
Thee the One, who art one thing and who art all!
So may Thou give to the intellect, wisdom to comprehend that one thing;
to the heart, sincerity to receive this understanding;
to the will, purity that wills only one thing.
In prosperity may Thou grant perseverance to will one thing;
amid distractions, collectedness to will one thing;
in suffering, patience to will one thing .
Oh, Thou that giveth both the beginning and the completion,
may Thou early, at the dawn of the day,
give to the young man the resolution to will one thing.
As the day wanes, may
Thou give give to the old man a renewed remembrance of his first resolution,
that the first may be like the last,
the last like the first in possession of a life that has willed only one thing.