Mase -- I'm Saving Rappers' Souls ... I Could've Saved Michael Jackson, Too

Mase intends to keep preaching in his church ... while he's rapping about extramarital sex -- and it's all part of his plan to spread the word of God to the hip-hop community ... a plan sparked by Michael Jackson's death.

TMZ broke the story ... worshipers at Mase's Atlanta church think he's turned his back on his congregation to go back to laying down sinful tracks like "Tricky Situation" ... with lyrics like: "I get the honey moaning, you marry her. She said she comin' home, don't you hurry her."

But sources close to Mase say he doesn't see any issue doing both jobs ... because he's really using his street cred to infiltrate hip-hop and ultimately plans to bring rappers closer to Christ.

Like a "Mission: Impossible" agent ... for Jesus.

Churchgoers tell us Mase has said his renewed spiritual calling was motivated by Michael Jackson's death -- and he feels he could have saved MJ if he'd been around to council him.

We don't know if anyone in church is buying this, but it's what Mase is preaching.