It means taking an action based on hope and expectation instead of your own power. Blind faith is based on pure hope. Reasoned faith is based on the reasonable expectation in a compelling power to achieve a compelling purpose. Indiana Jones' leap of faith was based on the present reality that his father was about to die, and that he himself would get shot unless he found the Grail, which, based on his experiences up to that moment, he reasonably believed had the power to cure his father, and that nothing else would work.
The object of the Christians' faith is an omnipotent God, not a tooth fairy or a leprechaun or a unicorn or something. We are faced with the inevitability that we will die, and there isn't a thing we can do about it. Many of us are also faced with the reality that we have a gaping hole in our hearts, and we cannot fill that hole with sex, women, drugs, alcohol, hard work, or anything else. It's a God-shaped hole that only God can fill. We also have an innate sense of eternity, and we strive to comprehend eternal things, and we strive to have the knowledge of our eternal destiny. Is the Christian faith reasonable? I believe it is reasonable. We can now peer inside living cells and see how marvelously complex they are. We can peer out into the universe and watch it expand before our eyes, and intuitively know that the universe as it is could not have arisen from nothing. We can consider our self-awareness and ponder how our minds and emotions and perceptions can work on the basis of chemistry and electrical impulses. We can open up the Bible and read about God's character expressed through the person of Jesus. It is reasonable to believe that the person of Jesus has the power to redeem our souls and restore our relationship with God, and give us the promise of new life.
To take a leap of faith, you need a compelling purpose, a compelling object, and strong reasonable substantiation. I believe faith in Christ meets those criteria. To take the leap, remember ABC. Simply think the following thoughts to God, who is with you right now: A: Admit you have sinned; B: Believe Jesus Christ died in your place; C: Commit your life to following God's ways the best way you can.
