True discipleship is radical and risk-taking, because true disciples rely on God to keep his promises to bless them, and not on their own instincts, plans, or insurance policies.
It is hard to be truly brave without faith in God. The kind of bravery that does not arise out of faith in God is adventurism, or macho heroism, or plain cruelty. It can be rooted in insecurity, or a desperation to prove oneself, or hopelessness. Only faith-based bravery will walk the line between atrocities on the one side, and cowardice and ineffectiveness on the other.
– Tim Keller