– Eric Auchard is a Reuters columnist. The opinions expressed are his own –

“There’s probably no God” runs the slogan of an advertising campaign humanists are running on buses across Britain. But if the supreme being has his doubters, few question the importance of Steve Jobs to Apple Inc.

In a letter to employees on Wednesday, the Apple co-founder said he would take himself “out of the limelight” for six months after learning in the past week that his still vaguely defined “health issues” are “more complex than I originally thought.”

While Jobs paints his absence as a temporary medical leave — he retains the Apple CEO title even as he steps aside — his departure leaves a spiritual void at a company most people think of as inseparable from the man.

The miraculous career of the prophet of the personal computer revolution, the self-made billionaire known for a career of second acts, draws frequent religious parallels: one biography of him is entitled “The Second Coming of Steve Jobs”.

In the 33 years since he co-founded Apple, Jobs has attracted the fervent devotion of his followers — the Mac faithful, and more recently, iPod and iPhone fanatics. To them, Steve is a secular messiah; to his detractors, a cult-leader.

Apple’s unmatched record of hit products has only been achieved under the famously tyrannical leadership of Jobs, whose obsession with sleek design and the hard to define “cool” factor of his gadgets is unique in the corporate world. Again and again, it is this aesthetic, and Jobs’ commercial success exploiting it, that have distinguished Apple products from so many copycat competitors.

On some level, anyone who has ever admired an Apple product harbors a little bit of the “design Nazi” in his soul. Managers who have endured Jobs’ withering demands to create nothing but “insanely great” products may have absorbed this.

But is culture enough to overcome a vacuum of leadership? Much as Microsoft Corp has become a smaller place since Bill Gates has wound down his role at the software giant and Apple adversary, Jobs can only be sorely missed.

How far can a company, its executives, engineers and salespeople go on the mantra, “What would Steve Jobs think?”

To be sure Tim Cook, Apple’s chief operating officer, is taking over Jobs’ daily responsibilities and Jobs said he will retain strategic oversight of the company’s direction while on leave. The pipeline of product innovation looks well-stocked.

If it’s a question of the man being bigger than the company, then Apple, which popularized the personal computer, the personal digital assistant and the handheld music player and is staking its claim on reinventing the mobile phone and, perhaps even, eventually, the television, is in big trouble.

CONTEMPLATING THE UNTHINKABLE

Inside Apple, the delicacy of Jobs’ planned absence was summed up in the innocuous headline given the company’s most dramatic announcement in years: The bombshell press release was simply entitled: “Apple Media Advisory.”

As if the only interested audience were baying reporters.

The news comes as a shock, but little surprise. It caps more than a year of widespread concern over the health of Jobs, aged 53 and a survivor of pancreatic cancer. More recently, his gaunt appearance and dramatic weight loss have added to the worries.

The immediate reaction to Jobs’ departure notice was a 6 percent decline in Apple stock. But the shares have fallen 60 percent after touching $200 at the end of 2007. It’s difficult to separate the impact of Steve Jobs’ health mysteries from the general decline all stocks have seen since then.

Wall Street analyst Shaw Wu argues that while Jobs deserves a lot of credit for the revival of Apple, “we believe the company has a deep bench and its culture of innovation and execution has more or less been institutionalized.”

Not so fast. Recall the dark years of Apple history starting sometime after 1985 and lasting until he returned in 1997. The famous Apple culture remained in place but product missteps and management in-fighting were the result.

The success of Apple has rarely been its technical innovation or engineering rigor. In that sense Cook is simply a placeholder. The company’s hit products all share a fascination with functionality and beauty that is unmatched in other gadgets. It is Jobs’ taste, his commitment to design and his micro-management of talent that drives Apple.

Jobs has pulled together Apple after the years of drift. That he has done so by being a control freak with a clear vision does not diminish his accomplishments. It’s hard to imagine how his despotism will be replaced.

– At the time of publication Eric Auchard did not own any direct investments in securities mentioned in this article. He may be an owner indirectly as an investor in a fund. For previous columns, click here. –