Earlier this month reports claimed the Hollywood actor was considering ditching the church if it meant possibly reuniting with Katie and his daughter Suri.
And now even Holmes is hoping for the same, reported Grazia magazine.
"Katie is a sucker for the big romantic gesture. Tom swept her off her feet the first time around, and if he goes ahead and leaves Scientology for her, that would be seriously tough for her to resist," a friend said.
Holmes filed for divorce from Cruise in June this year. Since their divorce was finalised, the 50-year-old actor has reportedly been suffering from lack of contact with his six-year-old daughter.
It is thought Cruise's connection with the Church of Scientology was one of the contributing factors to their break-up.
Holmes - who was raised a Catholic - reportedly didn't want Suri to be sent to a special Scientology camp or to be taught at one of the religion's schools.
"The religion is the biggest thing in his life. If he left that behind for her, it would be immense. But it seems that may be what he's talking about doing. He misses Suri like crazy," the source added.