Every summer, I have a recurring struggle with my faith.

From roughly Memorial Day until Labor Day, attendance at my church's services drops by a third or more.

We're a small congregation to begin with, so when our Sunday gatherings decline from our usual 70 or 75 people to 45 or 50, I get squirrelly.

On a purely intellectual level, I know it's just the annual summer slump. I've been a pastor since 1982. This has happened every year.

It seems to be universal. I grew up as the son of a minister, and I remember my dad and his preacher friends talking about summer slumps way back then.

On a more visceral level, though, I battle the resurrection of my shallowly buried fears. What if I've inadvertently said something that offended dozens of church members? What if attendance doesn't rebound? What if the church can't pay my salary? What if God has abandoned us?

Then fall arrives and all those folks who had wandered away for vacations and Sunday golf games stroll back into our house of worship.

And I breathe my annual sigh of relief.

It's possible I'm just an unusually neurotic pastor.

But my summer wavering might say something larger about the nature of faith.

The New Testament author of Hebrews — the writer's identity is a matter of debate — described faith as "the evidence of things not seen."

Yet most of us, most of the time, place our faith primarily in what we see right in front of our eyeballs, today.

I've known people, who believed, for instance, that God had healed them of some dreaded disease. They got a great report from the doctor, or 10 consecutive positive reports. They told everyone they were cured. Then they went back for the 11th checkup, got ambivalent results and immediately started planning their funeral.

Their faith mainly depended on what was happening at any given moment.

I'm not implying that we should ignore evidence we don't like, much less that we should avoid doctors or medical tests.

What I'm saying is this: Too often we base our faith solely on what we see right now. We forget the past and, if we're not careful, lose our hope for the future, just because a few things have gone awry.

I find it easy to trust that God is working among my congregation, that he's called me to my job and that he's taking care of my own financial and spiritual needs — until it looks briefly as if he's not.

Then the butterflies start. I grab the want ads.

The other day, a friend and I were discussing faith of another kind.

We talked of a couple we know: The woman cheated on her first husband, got divorced, but has for years been true in her subsequent relationship. We talked about another couple in which the man once betrayed his partner but has worked for a long time to prove his renewed, steadfast fidelity.

In both cases, the other partner, the one who has never strayed, has trouble trusting the one who previously erred.

"So," I asked my friend, "when does anybody ever arrive at a point where he says, 'This person has now earned my total confidence'?"

"Probably never," my friend replied. "No one can ever earn our confidence. We can never know anybody with 100 percent certainty. That's why faith in anyone is a choice. We just have to say, 'I choose to believe the best. I choose to trust.'"

That struck me as a pretty profound observation.

Faith is a choice.

I think that applies in our relationship with God, too.

If we're candid, we'd have to admit that, whether or not we tend to express it in these terms, we simply decided to believe God exists at all. We've never seen him. There's a lot of evidence for God — but there's a lot of evidence in the other direction, too.

At some point, we said, "I choose to believe."

Similarly, I've been at this pastoring business most of my adult life. I've had good periods and horrible periods. So far, though, my church has never shut down. I can't recall ever having one week in 27 years when the church couldn't pay my salary. I've watched my congregation rebound from slumps and doldrums time after time.

And so, what I need to tell myself is, "Summer slump or not, I'm going to believe that God remains in control and that he's doing terrific things here."

Maybe you've got some issue — with God or your spouse or your child or your boss — where you need to make that same type of intentional decision. To trust.