For me, the greatest tool for change and for introducing Truth is honest and guileless questioning. By honest and guileless, I mean questions that do not presume the questioner has all the answers any more than the System which is being questioned. Such honest questions understand that God and God alone is God.
We who are of Faith and we who are of Science of all people should not fear questions. Questions are what birthed modern Science. And questions are what births Faith. Copernicus questioned what everyone knew to be true, that the earth is the center of the universe, and in so doing launched modern science, all in good faith with Faith. Nathaniel came to Jesus with questions and doubts and Jesus called him "a true Israelite, in whom there is nothing false." Jesus loved questions, loved to ask them himself, and tore into question-haters with a vengeance.
Even the earliest accounts of dialog in the Judeo-Christian Scriptures begin with questions. The serpent challenges Paradise with a question: "Did God really say?" And when God comes to Adam and Eve after they have eaten the forbidden fruit (unquestioningly obeying the serpent, by the way), God starts His dialog with them with a question of His own: "Where are you?" In fact, He continues to ask a whole series of questions before He makes His first declarative statement, all these questions designed to poke holes in their unquestioned presuppositions.
The Story of the Fall looks like it is God pushing Adam and Eve away when in reality Adam and Eve have already pushed themselves away, only they don't realize it. Instead of questioning and querying God, they have ignored Him. And it will take several more chapters in Genesis before humankind finds a lasting way back to a God who has been pursuing them all along. "Where are you?" is, after all, a question filled with pursuit and desire.
The principle of this whole meta-story is that unless questions are raised to crack a System that does not allow questions, that way back will not be found – whether that System be post-Fall humanity, Phariseeism of Jesus' day, aging "Communist" Statism, the Religious/Political Right, the Religious/Political Left, or the modern god of Science. For all these human Systems resist what the true God never resists – honest and persistent questioning.
The problem with modern society today - be it Glenn Beck or Carl Sagan, Joe the Plummer or Susie the Seamstress (we are talking stereotypes here) - is that we don't ask enough honest questions. Oh, we raise questions alright, but those questions are more answers in disguise, and they are intended to replace one unquestionable System with another.
The surprising thing about Faith is that it comes in the most innocent and honest forms, birthed as babes in a basket of reeds or a shepherd's stable. Faith challenges the closed Systems of this world not with a sword, but with humility and doubt. Moses and Jesus both entered closed Systems in the least threatening way possible and their mere presence raised doubts that those Systems were all that unquestionable and impenetrable. It was babes, not equally imposing or threatening systems, that eventually overthrew the closed Systems of their day.
God never fears our honest questions, even questions that doubt His existence. For He created our minds to think and we damn ourselves to eternal darkness when we stop thinking and believe without question, as did Adam and Eve, that we have all the answers.