Mase -- My Wife & I Can Fix Your Broken Marriage ... But First, I Want a Divorce

How's this for ironic -- rapper-turned-pastor Mase -- who built a lucrative church and related business partly on his secrets to a successful marriage -- secretly filed for divorce from his pastor wife.

TMZ has obtained Mase's divorce filing in Georgia dated January 2nd, citing irreconcilable differences with Twyla Betha. And it sounded nasty ... Mase asked for full custody of their two kids and even wanted HER to pay HIM child support.

He claims they separated August 2013 -- after 12 years of marriage.

But just over a month later -- the day before Valentine's Day -- Mase inexplicably had a change of heart, filing to dismiss his divorce petition.

The fiasco is priceless -- if you look at the website for Mase's El Elyon International Church in Atlanta ... the entire thing is built around his successful relationship with his wife. The two even hawk their "successful marriage" book series called "What Do You Do After I Do?"

And the book description is perfect: "In this series, Mason and Twyla Betha share keys to build a marriage that will last a lifetime."

Define "lifetime."

We reached out to the Mase and his church ... radio silence.