He knew that within himself there was only sin and doubt. All his hope lay outside himself, in God’s word. There his security before God was unaffected by how he felt or how he did. And so, when facing doubt, he would not look within himself for any comfort (that would be faithlessness and sin, the origin of all anxiety, not the cure!); instead, he would hold before his eyes this unchanging, external word.
Regarding where Martin Luther found his hope:
