Doubt swells and surges

Doubt swells and surges, with swelling doubt behind!
My soul in storm is but a tattered sail,
Streaming its ribbons on the torrent gale;
In calm, 'tis but a limp and flapping thing:
Oh! swell it with thy breath; make it a wing, -
To sweep through thee the ocean, with thee the wind
Nor rest until in thee its haven it shall find.