14 Let us not then fear death, but let us only fear sin, and grieve on account of this. And these things I speak, not anticipating any thing fearful, God forbid! But wishing you when alarmed to be always thus affected, and to fulfil the law of Christ in very deed. For “he,” says Christ, “that takes not his cross, and follows after Me, is not worthy of Me.” This He said, not that we should bear the wood upon our shoulders, but that we should always have death before our eyes.
Even so as Paul, that is, died daily, and laughed at death, and despised the present life. For indeed you are a soldier, and standest continually at arms; but a soldier who is afraid of death, will never perform a noble action. Thus then neither will a Christian man, if fearful of dangers, perform anything great or admirable; nay, besides this, he will be apt to be easily vanquished. But not so is it with the man who is bold and lofty minded. He remains impregnable and unconquerable.
As then the Three Children, when they feared not the fire, escaped from the fire, so also we, if we fear not death, shall entirely escape from death. They feared not the fire (for it is no crime to be burnt), but they feared sin, for it is a crime to commit impiety. Let us also imitate these and all such, and let us not be afraid of dangers, and then we shall pass safely through them.
Source: Homilies on the Statues (New Advent)