Not to be confused with Michael Johnston Democratic legislator in Colorado.
How Michael said he found Jesus
Well, after he got HIV he told people that with the help of Jesus he had overcome the temptation to be gay. Johnston got involved with the Conservative Christian movement and started something called Kerusso Ministries where he kept telling people that he'd stopped being gay and as such, others could as well, see Harm the ex-gay movement causes. Michael Johnston spoke at churches and schools, on radio and television, and even Jerry Falwell used Johnston to put the Falwell message out. As a result, men who couldn't stop being gay the way Michael Johnston said he had got to feel inferior.
Did he really find Satan?
It seems Johnston had been calling himself Sean and contacting men online and he's been doing gay parties where he had unsafe gay sex and didn't get round to telling his partners about the HIV. Johnston spent just so much time with the worst type of Christians who say AIDS is a punishment from God so perhaps he got irresponsible about spreading God's punishment around. Anyway we Liberapedians think spreading the AIDS virus like that amounts to murder. Johnston had to close his ministry down after that and a good thing too. There's no reason to believe that Satan exists so we must assume his own irresponsible and selfish lying nature made him do all that. Conservative Christians also lied, pretending Johnston was straight when they knew had been having unprotected gay sex.
For at least eight months, the pious Religious Right was aware that Michael Johnston was having sex with men. They knew that in the past he had sex without revealing his HIV status and that he might do it again. The right wing also knew that their propaganda promoting Johnston was a lie. Yet, they continued to promote his myth of change, destroying families and lives in the process. 
Repentance and restoration twice over
Well yet again Johnston says he's repentant and ex-gay. After the truth came out Johnston got into something called, Pure Life Ministries and says he's now pure again. Do we believe him? What alias will he use next?
“Many people are still behind him, and we think he did the responsible thing by closing the ministry down,” LaBarbera added." 
Which people are still behind him after he was found out doing what amounts to murder? (Much like what a subculture of the gay population do, namely bugchasers, but most of them don't mean it, it's just a fantasy. ) Well having men behind you doesn't matter so long as both of you like it that way but if you've got something like HIV you should use a condom and warn your partners. But that's if your sober enough and both haven't taken anything illegal.
Far too often Christian morality means making it look as if you're righteous and hoping nobody finds out what you're really doing. If you're caught you pretend you're sincerely repentant.
Can gay people change?
There are too many stories of people desperate to become heterosexual who can't. Furthermore there are too many stories of people who say they've changed but later realise the change wasn't complete or get caught doing something with their own sex that they wouldn't admit openly. Some Bisexuals probably have a choice whether they express the gay side of their nature, the straight side or both. Despite this many people appear to have no choice.
People who claims that they can make one "straight" sometimes are lying to get money form those they pretend to help though they subject themselves to further ridicule and discrimination of a scale that's worse than before if they're found out.
Furthermore, we can't prove definitively that all those who have claimed to have become "straight" have continued to have "secret sex" with persons of the own gender. Just many have been caught that way.