From an earthly perspective, many of the prophets of the Old Testament got a raw deal. On this list, we certainly must include Jeremiah. He was forbidden to marry and have a family, he couldn't attend parties or funerals, and he prophesied in a time that was utterly hostile to his message. As a result, he was imprisoned, put in stocks, dumped in a cistern, and threatened with death. Even his own extended family plotted to kill him.
This makes for grim reading, and it wasn't a whole lot of fun for Jeremiah to live through, either. Frequently, he complains to God about his lot in life, but God's replies are generally unsympathetic. In such circumstances, it would have been easy for Jeremiah to give up on God, but Jeremiah knew very well that he didn't dare. At the very beginning of his work, God tells him in Jeremiah 1:17, "But you, dress yourself for work, arise, and say to them everything that I command you. Do not be dismayed by them, lest I dismay you before them."
In other words, there was exactly one way that Jeremiah could hope to survive the dying convulsions of the kingdom of Judah. He had to stay 100 percent faithful to God. If he wasn't, if he allowed fear to deter him from proclaiming God's word, God would meet his silence with the very woes he hoped to avoid. Even though serving God looked like the riskiest choice, it was actually the safest.
Today, few of us have lives that can compare to Jeremiah's for sheer wretchedness. We enjoy many of the blessings he was not allowed to experience, and we don't have his surfeit of enemies. However, even in much less trying times, we still experience the temptation to disobey God because of fear. We go get drunk with our friends because we're afraid that they won't be our friends anymore if we don't. We return evil for evil in our marriages because we're afraid that if we don't, we'll get walked on. We're as touchy as a fresh burn because we're afraid that others won't respect us if we aren't.
And so on. The devil will attempt to use our fears against us in innumerable ways. However, as with Jeremiah, the only way forward is to defy our fears for God's sake. If we allow ourselves to be dismayed before our spiritual enemies, He will dismay us before them.
This is generally not obvious at the moment. At the moment, it seems that only by giving in to our fears can we protect ourselves. We must remember, though that protecting ourselves isn't our job. It's God's. If we are faithful to Him, He will be faithful to us.