When Oscar-winning director Paul Haggis resigned from the Church of Scientology last week with a scathing letter, he revealed that the church has a policy of forcing its members to disconnect from people who are seen to be nonbelievers or enemies of the religion.

And for a lot of Katie Holmes’ friends, it was like a light bulb had switched on above their heads. Because ever since she wed devout Scientologist Tom Cruise in 2006, friends have been complaining that Katie has cut herself off from them and the life she used to live.

“Since tying the knot with Tom, she’s become estranged from all of her close friends and she doesn’t even make excuses for it,” a pal tells BettyConfidential. “She’s become very cold. The only friends she talks to are Tom's Scientology buddies, who are now her friends as well. She’s even changed her cell phone number because she is tired of people calling and saying, ‘Where have you been?’ ‘Why haven’t you called me back?’"

The insider adds that Katie doesn’t even realize she's changed. She thinks her old friends just don’t understand her new life. “She doesn’t see that her friends are hurt by her new attitude,” the confidant says, adding that Tom has been encouraging Katie to cut loose her old friends in order to have room for the growth in her new life.

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But Katie isn’t blindly agreeing to everything that Tom suggests. Earlier this year, when she was filming Don’t Be Afraid of the Dark in Australia, the couple reportedly butted heads when Tom flew down there to visit her and lay down the law. “Katie tried to be her own person and stand up to Tom,” the source says. “She doesn’t want to be just Mrs. Tom Cruise. But she gets frustrated and then gives up. It’s like she doesn’t have the strength to fight.’’