The Expectation of Utopia
The secularist worldview does not acknowledge the fallenness of humanity, which leads to the expectation that a true utopia is possible. That expectation leads to an inherent dissatisfaction with life because every imperfection is held up to the standard of a perfect utopia, and that often gives rise to the frustration that some external force is holding us back, and someone is to blame.
It's like a person slaving away at a perpetual motion machine. He will constantly be frustrated with his failures because he doesn't understand that the laws of physics make his goals unachievable.
Christians, however, should understand that mankind is fallen, and that makes a utopia an impossible goal. The Christian's goal is instead to maximize justice, minimize human-caused suffering, and to structure our institutions in such a way to counteract as much as possible the fallenness of humanity.
Instead of slaving away at making a perfect perpetual motion machine, we ought to work at making an optimal machine, with constant adjustments to counter all of the forces working against it. Utopia isn't our standard, and it's actually a harmful standard because it allows us to forget that the failure of the machine comes from within every one of us, not just some other person who won't get with the program.
Recognizing the fallen nature of mankind removes from us the expectation that our lives will be perfect, crime will go away, everyone will be rich, wars will cease, all disease will be cured, and no one anywhere ever needs to feel emotional distress. Even in a hypothetical maximally optimal world, these things will still exist.
Our standard should be to do the best with what we've been given, to fight evil starting with the evil inside us, to serve others according to the way shown to us by our Creator, and to live lives of meaning in defiance of the darkness in this world.