Having clear and well defined goals provides motivation. Likewise, the absence of such clarity produces discouragement and doubt.
I know the story of a naval officer who decided to retire early. When asked by a family member why he decided to do that, he said: “I enjoyed being in the Navy during the war. Not that I liked war, but back then we all knew the purpose for being there and what we should do. The problem of the Navy in times of peace is that we don’t know what to do and it left me unmotivated.”
Meditate on the text of Philippians, chapter 3, verses 13 and 14:
Brethren, I do not count myself to have apprehended; but one thing I do, forgetting those things which are behind and reaching forward to those things which are ahead, I press toward the goal for the prize of the upward call of God in Christ Jesus.