The tweet garnered concern from fans, with many questioning why Joshua wouldn't have done more research before choosing to get baptised at the church, reports aceshowbiz.com.
"Drive by baptism? Lol. If you truly believe in the purpose of being baptised why would you not research the people doing it," wrote one user.
Another wondered: "Nahh wait. You didn't research the church before getting baptised by them?"
Conversion therapy is the widely discredited practice of attempting to "cure" somebody's sexual orientation or gender identity through various means, including shock torture.
The United Nations and World Health Organisation have both condemned the use of conversion therapy.
The buzz arrived after Joshua uploaded a short video taken from a recent service at Bethel Church in Redding, California, in which he's seen on stage with a leader who asks about his decision to get baptised.
"Long story short, I grew up Christian and I ran the other way, as far as I could go in pursuit of truth and that only ended in addiction, depression, suicidal ideation, eating disorders, et cetera," he said in the clip.
"And no other teacher gave me anywhere near the peace that Jesus Christ did," he concluded as the congregation broke into cheers and applause.
Joshua recently publicised his belief in Christianity on Twitter in the last few weeks.
On January 5, he tweeted: "Jesus Christ is the only way. His death and resurrection are historically documented. Turn away from hate, seek forgiveness and come home to Him."
Joshua also shared his spiritual journey during an interview with Rolling Stone. "A few months ago I asked God to 'send me a sign when I write the truth.' I typed 'Jesus is the way,' nothing happened, then I added, 'Jesus is the *only* way' and the light turned on in my living room," he said, adding "I have also first-hand encountered Jesus twice."
"The experiences were richer and more vivid than anything in my entire life. I look forward to speaking about it soon," he shared, and concluded: "For those concerned about me be sure of this: I'm better than I have ever been. The peace I feel is far beyond what I thought possible."