"Impossible."
All too often that is our human response to the notion that God conveys grace through means like the sacraments. Perhaps, in America, we are too steeped in a Christianity influenced heavily by a Zwinglian flavor of Reformed thought or an overly-sensationalized, Pentecostal television ministries. Perhaps, in 2013, we are too intellectually-sophisticated to believe that God would choose to work through things as mundane as water, bread, and wine.
Such struggles are not new. Tertullian wrote about the human tendency to expect God to work only in the spectacular in the second and third century. In his work, On Baptism, he wrote:
There is absolutely nothing which makes men's minds more obdurate than the simplicity of the divine works which are visible in the act, when compared with the grandeur which is promised thereto in the effect; so that from the very fact, that with so great simplicity, without pomp, without any considerable novelty of preparation, finally, without expense, a man is dipped in water, and amid the utterance of some few words, is sprinkled, and then rises again, not much (or not at all) the cleaner, the consequent attainment of eternity is esteemed the more incredible.
Some things never change, do they? Neither our tendency toward disbelief...nor God's condescension to lavish his grace upon us plainly and wonderfully.