"Smallness of Soul"

"[R]eading Thomas Aquinas (1224-74) on the virtue of courage, I happened across a vice which he called pusillanimity, which means 'smallness of soul.' Those afflicted by this vice, wrote Aquinas, shrink back from all that God has called them to be. When faced with the effort and difficulty of stretching themselves to the great things of which they are capable, the cringe and say, 'I can't.' In short the pusillanimous reply on their own puny powers and focus on their own potential for failure, rather than counting on God's grace to equip them for great work in his kingdom--work beyond anything they might have dreamed of for themselves." 

Rebecca Kronyndyk DeYoung, Glittering Vices: A New Look at the Seven Deadly Sins

Another example of the need for Christians to dare greatly through the power of the grace of Christ.

Daring Greatly by Paul

"Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with endurance the race that is set before us,2 looking to Jesus, the founder and perfecter of our faith, who for the joy that was set before him endured the cross, despising the shame, and is seated at the right hand of the throne of God. 3 Consider him who endured from sinners such hostility against himself, so that you may not grow weary or fainthearted." Hebrews 12:1-3 ESV

The Man in the Arena