"Then Caleb quieted the people before Moses, and said, 'Let us go up at once and take possession, for we are well able to overcome it.' "
Caleb's attitude (above) is not just secular "positive thinking." Instead, it is faithful confidence, based on his knowledge of who God is, and of how He (the Lord) keeps His promises. What do we have before us today, that must be "conquered": a sinful world, the need to sell something, some sinful habit?
Whatever it is, what do we have to lose, by employing our faith, and trusting that God can (and will) handle it? The bigger the problem is, and the more impossible it seems--the better. The Lord enjoys overcoming humanly-impossible situations; and delivering His children in and through them.
[Puritan quote of the day: "True saving peace loves to be examined, it is willing to be examined, it loves to be tried." --William Bridge, in "A Lifting Up for the Downcast"]