Joy, rather than happiness, is the goal of life, for joy is the emotion which accompanies our fulfilling our natures as human beings. It is based on the experience of one's identity as a being of worth and dignity.
The relationship between commitment and doubt is by no means an antagonistic one. Commitment is healthiest when it's not without doubt but in spite of doubt.
The opposite of courage in our society is not cowardice, it is conformity.