Perry Noble, the now former pastor of Newspring Church in South Carolina, has been forced to step down. He joins a melancholy list of high-profile megachurch pastor casualties, fallen warriors brought down by the temptations of money, sex and power.

On the other hand, it doesn't usually take long for them to respawn and get back in the game; Mark Driscoll's new church in Phoenix is doing pretty well, at least by his own account, and Todd Bentley is up and about too. Noble – a gifted evangelist – is probably not finished with ministry yet, but it remains to be seen whether he will return after a decent process of repentance and restoration.

Where did it all go wrong? Noble's former board of directors cites his "posture towards his marriage, increased reliance on alcohol and other behaviors" for his removal. Noble himself says he "began to depend on alcohol for my refuge instead of Jesus and others". Note we aren't told whether he is an alcoholic, though he is "under the treatment of an excellent psychiatrist".

What's interesting, though, it Noble's self-diagnosis, in which he places the problem further back. He drank, he says, because of his obsession with church growth. Newspring grew from zero to 30,000 members in 16 years, and Noble admits to an "obsession to do everything possible to reach 100,000 and beyond" which had "come at a personal cost in my own life and created a strain on my marriage".

Whether he's right to link that strain to his alcohol problem is an open question. Though we aren't told whether he is an alcoholic, the condition doesn't lend itself to accurate self-analysis.

However: his admission that he was obsessed by his aim of reaching 100,000 members is perhaps the most troubling thing about this whole story. It indicates a fundamental failure of theology that's an indictment not only of Noble himself but of an entire church culture. Because Noble is not alone in his obsession with numbers.

To set a target for church growth – any target – is to hijack the work of the Holy Spirit. It's a fundamentally secular approach to ministry that has no place in the Church. At its worst, it's an expression of monstrous hubris, in which the personal ambition of a few individuals is described as "what God told me". It warps pastoral practice, skews evangelistic motivation, narrows the understanding of the Church's mission and all too often leaves its promoters to crash and burn. And this is why it's wrong.

1. Only God decides how big a church should grow

People who come to church do so because they are made in God's image, infinitely precious and valuable to him, endowed with the ability to think, to experience joy, love and beauty, and to respond to God's infinite love made personal in Jesus Christ. They are not figures on a balance-sheet. Another convert is not a step toward a target. The Church is not a business, where progress is measured by numbers. Every person in a congregation is there because God has drawn them there. Ministers are channels of God's grace, not chief executives.

2. Size is nothing to boast about

No one denies that big churches can do things that small ones can't. But that's a long way from saying that they're better. They face temptations small churches don't. They can become reliant on their money and facilities, they can be proud of their presence and influence, and there's something seductive about worshiping with thousands of other people. The lessons of Scripture are that God is not interested in money, power or numbers. He tells Paul his "power is made perfect in weakness" (2 Corinthians 12:9). We worship a crucified Saviour. The greatest churches in the world today aren't in South Carolina; they're in the Middle East, where Christians face death all day long for the sake of the Gospel.

3. Numbers don't matter: quality does

A relentless focus on evangelism and church growth can deliver results, in the same way that a highly proficient advertising campaign can. But the test of discipleship isn't whether someone prays the sinners' prayer, gets baptised and signs up to be a member. It's how the full, rich, abundant life of Christ grows within them, reshaping them in his image. The culture that focuses on evangelism as the number one priority for the Church has failed to grasp the wholeness of the gospel. We are not "reborn to reproduce", in a sterile parody of Darwinian natural selection; we are reborn to become Christlike, and it's Christlikeness that draws people to Christ. A church that focuses on growth in numbers to the exclusion of everything else will never be a healthy representation of the body of Christ.

Will Perry Noble find his way back into ministry? Let's hope so. But on the basis of what we've been told, alcohol is the least of his problems. There's a fundamental misunderstanding about what he's been called to – and one that's shared by far too many in his evangelical sub-culture – that has to be challenged and resisted. "Unless the Lord builds the house, the builders labour in vain" (Psalm 127). God builds churches if He wishes. Pastors, no matter how gifted and charismatic, don't get to decide.

Follow Mark Woods on Twitter: @RevMarkWoods