I think that faith is a lot like friendship.
There are many cases where this is true, but never more than when life is difficult. Say you’ve got a friend, somebody who is a lot of fun, but you never see them when you’re having a difficult time. They’re never there to support you unless you’re doing something awesome and fun (I don’t currently have any friends like that, but I’m sure we’ve all experienced this at one point or another). On the faith side, it’s really easy to believe in God when your life is great (or believe in anything, really, be it sports, politics, or your job). Things are perfect, and you say, “Thanks, God, for making my life fantastic!”
And then something rotten happens, for example getting into a bad car accident followed by a period of bad health or something else difficult, and the impulse is to say “God has left me and I no longer believe in God’s power.” At the same time, those fairweather friends are nowhere to be seen.
True faith (and friendship) is sticking it out through the good and the bad, because it’s the relationship that matters, not what you are (or aren’t) getting out of the relationship. Be a good friend in happy times and the hard times, and don’t lose faith because things are rough (even though it’s difficult not to).