Some people believe that religion is about comfort, reassurance--God loves us, we continue on after death, wrongs will be righted, etc.
Those things are true. But it is not about comfort.
Christianity--Christ--confronts us with the reality of our sin. Silently, humbly, meekly. He shows us in His Flesh what our sin has done, what it looks like. He strips away every lie that we tell ourselves. And if we are awake, it will wrench us to our very core.
It is not about comfort. It is about mercy, and Love. And those are very uncomfortable things. They do not deny the ugliness that is in each of us, but seek to redeem it and transform it. Before we can be healed, we must see our disease for what it is.
And from the Cross we learn that transformation hurts; that the only road to beauty leads through suffering.