At my church we recently concluded a sermon series in which we answered questions submitted by the congregation. One of the submissions read, “Do miracles really happen?”

I regularly talk with people who consider themselves Christians, who judge God’s existence to fall in the realm of reasonable belief and find Jesus admirable and worth imitating. But seas parting and blind eyes seeing and dead men walking? It strains credulity too far. They laugh at the suggestion.

I asked a young man who had this opinion of things why he came church. He replied in surprise, “Because it teaches people how to be good.”

For some, it’s conceivable God could guide Rebekah to be in the right place at the right time. A tiny mental nudge, after all, doesn’t violate too many natural laws.

But Sarah is another story. Either she’s barren or she’s not. Give modern science a close-up gander at her womb, and it will tell you definitively what’s possible and what isn’t.

The conversation around miracles is often framed as a debate over whether God is allowed on exceptional occasions to intervene in the world and break the established rules.

The trouble with this debate is the premise itself. In the biblical imagination, God’s involvement in the world isn’t the exception but the rule. History is shaped by God and humans together, both acting and responding to each other’s movements.

“Miracle” is a name we give to an instance of God’s involvement that stands out to us. But God is intervening all the time, whether we notice it or not. The Bible suggests we have not even begun to conceive of what a world, what a life, would look like in the absence of God’s activity.

To believe this is the truth about the world is a leap of faith. Just as it is a leap of faith to believe the world is closed to God. However, it seems to me that today more than ever, it is a necessary one.

Because a Christianity without miracles is only a shell of itself. A Christianity without miracles depends on our own power for all change and our optimism for all hope.

Yet, every day shows us how human knowledge falters at the most crucial moments, unleashing problems it is powerless to solve. Things come apart faster than we can fix them.

In the face of our dark headlines, optimism fails. The most resilient crusader grows weary and eventually comes to the end of his or her personal resources. What then?

Belief in God’s involvement is not a guarantee of always getting the outcome we want. It’s not a surety against all suffering and loss. It’s not an excuse for us not to act or do our part.

But it is a promise that we are not all that there is. It is an assurance that when all the lights go out, a candle still remains. It’s a reminder that there is reason to hope even against all hope.

It’s also a guard against the temptation to lie to ourselves, to deny that things are as bad as they seem.

We can own the truth, because we know that even where death has won, love can yet return an impossible victory.

In Christianity, miracles are not secondary to ethics. They are not incidental. They are the very heart of faith. Because Christianity is not a system to show people how to be good. It is foremost a declaration that God is good, beyond our wildest imag­i­nations, beyond our most catastrophic failures. And because of that goodness, life will yet emerge from the deadest of wombs.

The good news for a skeptical church is that Sarah’s incredulous laughter doesn’t preclude the miracle. God acts in power and in mercy anyway. May God turn our doubtful chuckles to a belly-laugh of joy.

Meghan Larissa Good is teaching pastor at Trinity Mennonite Church in Glendale, Ariz., and  author of The Bible Unwrapped: Making Sense of Scripture Today, published this month by Herald Press.