Although the Magid of Chernobyl was a gaon in Torah with a brilliant mind, he still knew when to act with complete simplicity, as can be seen from the following story:
The chassidim of R' Motel of Chernobyl saw him standing by the window moving his lips. They came close to hear what he was saying, imagining he was saying some deep Kabbalistic prayer. They were shocked by what they heard; the Rebbe was saying: "Ribono Shel Olam, the maid that helps out my wife wants to quit, but my wife really needs her help, so please make the maid change her mind." The chasidim couldn't believe what they heard, and asked the Rebbe why he, the great gaon, was praying like a simple person, asking Hashem for such a simple thing. Replied the Magid: "Who else should I ask?"
An invaluable lesson can be learned out from this story. Now matter how minor something may seem, we should turn to Hashem and ask for it. Nothing is too big or too small for Hashem, as this great gaon demonstrated that we need Hashems help for everything. This shows real pure emunah, when for each and every thing we need, we ask Hashem for it, and only then go about our hishtadlus to get what we need.
See Heicha HeNegina for more on R' Mordechai of Chernobyl.