Positive psychologists have proven that positivity leads to success, but most Christians in America have chosen to believe a single eschatological theory that leads to pessimism and cynicism. Pessimistic Christians put themselves in Christian bubbles and focus on self-preservation, and when a mind is clouded by negativity, interpretations of biblical prophecy lean toward the pessimistic possibilities. 

The fantastic writings of the Left Behind books have popularized premillennial dispensationalism with good intentions, but that interpretation of biblical prophecy teaches that sinfulness will continually increase until Jesus throws up his hands in disgust and secretly raptures worthy Christians, leaving behind unworthy sinners to suffer the wrath of the antichrist. Teaching that questionable theory produces negativity that hinders the Christian mission. 

When Christians believe that they cannot succeed in leading most of the world to Jesus, they will fail to put in the effort that success would require. Jesus, on the other hand, taught his followers that nothing will prevail over his church, and that teaching inspired them to sacrifice everything for the Christian mission. This is not a promise of prosperity without effort or of inevitable success, but biblical positivity is an energizing force that will help Christians flourish.