True Christian spirituality has always emphasized perseverance: "To those who by persistence in doing good seek glory, honor and immortality, he will give eternal life. But for those who are self-seeking and who reject the truth and follow evil, there will be wrath and anger" Romans 2:7-8, italics added.
Righteousness--true holiness--is seen over time in our persistence. It is relatively easy to "flirt" with righteousness--being occasionally courteous to other drivers (if you happen to be in a good mood), helping someone in need by opening the door for them (if you have time), throwing a few extra bucks into the offering plate (as long as you won't miss them). But this behavior is in reality superficial righteousness. The righteousness God seeks is a persistent righteousness, a commitment to continue making the right decision even when, perhaps hourly, you feel pulled in the opposite direction. Holiness is far more than an inclination toward occasional acts of kindness and charity. It is a commitment to persistent surrender before God.
What gives us the power to persist in doing good? Paul in Romans 2:7-8 notes that in our persistence we seek "glory, honor and immortality". These are words that point to an alternate history, to an afterlife (there is, after all, no immortality in this world). Persistence doesn't make sense unless we live with a keen sense of eternity.
From Sacred Marriage by Gary Thomas