The prayer Mother Teresa’s Missionaries of Charity say before leaving for their Apostolate:
Dear Lord, the Great Healer, I kneel before you, Since every perfect gift comes from you. I pray, give skill to my hands, clear vision to my mind, kindness and meekness to my heart. Give me singleness of purpose, strength to lift up a part of the burden of my fellow suffering men [sic], and a true realization of the privilege that is mine. Take from my heart all guile and worldliness, That with the simple faith of a child, I may rely on you.
Reposted from Kurt Miller's blog: http://www.letincensearise.com/