God has chosen certain people for very specific roles at different times. Consider Abraham: without Abraham, how and when would monotheism have gained a lasting presence in the world? Or Moses: without Moses, how and when would the world have gained the idea that the worship that pleases God is when we treat each other with honesty and compassion? In both of these cases, Christians will see the hand of God -- and yet God chose to work through a person. We can honestly say that the world is different because of the people through whom God works, like Abraham and Moses. And in both cases they were just the beginning, and the world began to fill with a stream of people who saw their service to God in terms of honesty and compassion towards their neighbors.
It's unfortunate that so many arguments have occurred surrounding Mary, mother of Jesus. She also holds one of the era-defining roles in history. And the virgin consented to remain a virgin while others would think of her as an immoral woman. That is so different from the way of the world, where so many of us would gladly settle for the appearance of decency, for hiding our sins, if only we could keep our reputations. Here's the temptation: Will the appearance of being good become more important to us than the reality? For Mary, the reality was more important than the appearance. In some small way she shared in her son's suffering, if only for a short time: numbered among the transgressors, despised and rejected without deserving it.
And again God chose to work through a person. The world is different because of Mary. "Wait," someone might say, "All she did was bring Jesus into the world." Well, that's like saying "All Abraham did was move to a new place." Some of the world-changers didn't do complicated things. Some of the controversy about Mary has been this: By focusing on her, do people take credit away from God? How much mention of her is appropriate? In Scripture, she focuses not on herself but on her son. That's exactly how she brought light into the world.
Since everything happens because of God, it is easy to think that we do not matter. But God has chosen to make a world in which we matter. God typically works through people. When he heals people or rescues people, it's generally done through someone else with human flesh and blood. Our struggles matter. When he feeds the hungry or visits the sick, it's through us. Even in matters of redemption, at every point we see that people matter. That is, after all, the point of redemption.
In dark times, we are called to bring light into the darkness. We are the vessel that carries Christ. For those hostile to Christ, we carry a quiet and humble form of Christ: feeding the hungry, visiting the sick, and serving God by honesty and compassion towards our neighbors. Because God works through us, and we matter.