When Rowena Cross and her husband Ron went on holiday last summer, they didn't imagine it would turn their lives, and the life of their church, upside down.

As Rowena tells it, she was relaxing on a beach when Ron – vicar of St Saviour's church in Sunbury-on-Thames, Surrey – told her he felt they needed a bigger vision for the church.

As the church's director of mission, evangelism and discipleship, she'd previously had visions of Christians worshipping at the town's famous Kempton Park racecourse – and this, she realised, was what God was calling them to do.

She tells Christian Today how a series of remarkable events led to everything falling into place. She approached the racecourse with her request, saying 'There's nothing in it for you, you'll have to give it to us for free.' 'OK.'

A conversation with a friend led to contact with the European director of the Luis Palau Association, Dave Plowman, and an offer by evangelist Andrew Palau to come and speak – LPA also offered to book all the bands for the main worship event. Another conversation led to the involvement of the Philo Trust, headed by evangelist JJohn, and still another to the involvement of New Wine. As it happened, the only weekend Kempton Park could offer fell on the National Weekend of Invitation (formerly Back to Church Sunday) – its director Michael Harvey came and offered evangelism training to the local churches. The Bishop of Kensington is closing the event.

It has, Rowena says, been an extraordinary journey for a church that, while flourishing in many ways, could never have put on an event like this by itself. 'Only God could have done that. At every opportunity God has provided us with what we need – sometimes before we even knew we needed it,' she says. 'We had no money, no budget, nothing. It's about going beyond what we're capable of doing as humans.'

Along with the evangelistic outreach is a practical service project they've dubbed Love Sunbury. They aren't seeking great publicity for it, but it's about social transformation. The Saturday of the weekend will see teams going out painting and litter picking – and evangelism and social action will come to a head with a new 'Feeding of the 5,000' at the racecourse on Sunday.

They've partnered with Feed the Hungry and with supermarkets to offer free food to anyone who wants it – a very considerable extension of the ministry the church already has to the local area. Every week it feeds 150 people who use its foodbank.

Sunday morning's event is called Joy @ Kempton Park. There'll be music from performers including Duggie Dug Dug, Noel Robinson, Throwback Kid Pete James, Daughters of Davis and X-Factor finalist Tracyleanne Jefford, a Sunbury native – all of them professional, high-quality acts. Andrew Palau will preach, and everyone will eat together.

'My desire is that Christians will come to life and that people come to hear the gospel,' Rowena says.

The other local churches are all involved.

'The important thing is that this is kingdom focused. We needed other churches to come on board for that. We're praying people into the kingdom and we need them to be physically taken to church the next week. I've said to the other churches, if you aren't there, you can't take them to your church.'

The terraces at Kempton Park hold about 20,000 people. Is she nervous? Well, yes. But, she says: 'Everything in my heart is telling me that I can't believe God would provide the people, the resources, the Spirit – everything – if he's not going to show up.

'Are we prepared to take risks as Christians? Yes.'

And so, she says, if you're anywhere near Sunbury on Thames, 'Turn up and bring someone with you.' And if you aren't: 'Pray for us. Pray that God sends thousands who don't know Jesus. Pray for protection for the core team, and pray for revivial.

'For me, the message to any church is that God can and will use you if you step out.'

And, laughing: 'Be bold, stop faffing about and crack on for Jesus. That's my message to the global church.'

Joy @ Kempton Park is at 10 am on Sunday June 17.