In the wake of Hurricane Harvey and the ongoing flooding in Houston, Texas, Joel Osteen has officially opened his megachurch as a refuge for the thousands who are now homeless. It comes after the pastor faced a barrage of criticism online when it was implied that the prosperous Osteen was withholding shelter from the needy in a time of crisis.

'Houstonians, Texans, are generous people, gracious people. We like to help others in need. That's what you're seeing here today people stepping up and you know and helping these people that have been displaced,' Osteen said on Tuesday, announcing the opening of the 16,000-seat arena belonging to his congregation, Lakewood Church.

Lakewood Church spokesman Don Iloff told the Washington Post that the church building had earlier been flooded, making it unsafe as a shelter – but he hit back at claims that church had closed its doors to the desperate.

'We were never closed,' he said. 'This is crazy. People are saying we've locked the church. The church has been open from the beginning, but it's not designated as a shelter.'

The water had receded by Monday, Iloff said, and the church became a shelter on Tuesday.

He added: 'The problem with that building is it's prone to horrific flooding. ... If that building starts to flood, it floods in an instant,' he said, explaining why it hadn't been opened sooner. 'If we had people on the first floor, you'd be writing a whole different story. I'm telling you, it'll be horrific.'

According to Associated Press, a now-deleted Facebook and Instagram post put out on Sunday by Lakewood associate pastor John Gray had read: 'For the people spreading lies about my church. If WE could get there WE WOULD OPEN THE DOORS. As soon as the highways aren't flooded please know @lakewoodchurch will do all they can alleviate the pain and suffering of as many people as possible. Love y'all! #CantStandLiars.'

Much frustration was subsequently directed online towards Osteen, a popular, wealthy and controversial 'prosperity gospel' pastor. Tennessee megachurch pastor Greg Locke tweeted: 'Joel Osteen, as a Pastor you have a huge obligation to show the love of Christ at this very moment. OPEN THE DOORS'.

Some defended the pastor and his 38,000 member church. Twitter user James Ritchie posted: 'I support Pastor Osteen's decision to NOT open his church. It's a house of worship NOT a shelter.' At least 20 people are confirmed to have been killed in the wake of Hurricane Harvey since it engaged Texas on Friday. Large parts of the state have been submerged underwater, and thousands have been forced to flee their homes. A night curfew in Houston has been established (running from 00:00-05:00 local time) in a bid to curtail crime, looting and armed robberies, according to BBC News. In the affected areas, more than 13,000 people have been rescued. Since opening as a designated shelter, Lakewood has been emphatic on social media about its availability and the need for volunteers. The church tweeted yesterday: 'Thank you Houston. Your response has been overwhelming. We cannot thank enough the hundreds upon hundreds of volunteers who came out today!'