I have a mustard seed and I’m not afraid to use it.
Attr. (falsely, not to spoil the ending or anything) to Pope Benedict XVI, who would never have used such a colloquial American-sounding phrase. I’m fine with colloquial Americanisms, but I find it unlikely in the extreme that B XVI is familiar with them, much less familiar enough with one to use it like this.
Pope Benedict did talk about the mustard seed in one of his interviews with Peter Seewald, and apparently around the time of his election a commentator used the saying that became the fauxtation to summarize his views of then-Ratzinger’s approach. It then got picked up by a few other people, then got used in quotation marks without attribution as the title of a blog post, and thence passed on into fauxtationdom.