If we want to be spiritual, then, let us first of all live our lives. Let us not fear the responsibilities and the inevitable distractions of the work appointed for us by the will of God. Let us embrace reality and thus find ourselves immersed in the life-giving will and wisdom of God which surrounds us everywhere.
From Thoughts in Solitude by Thomas Merton
(Farrar, Straus and Giroux, Publishers, New York, 1958) Page 46-7.
I think I am all too prone to "fear the responsibilities and the inevitable distractions of the work appointed for [me] by the will of God."
I'm not sure if saying, "Once bitten, twice shy" actually amounts to a sin in itself, but it can most certainly lead to missing the mark, which is what the OT Hebrew for sin means, after all. "God did not give us a spirit of cowardice, but rather a spirit of power and of love and of self-discipline." (2 Tim 1:7)