He has considered if asked if the enquirer might hold his hand for a couple months until he gets back in to his groove. That might drive away the Witnesses faster than anything.
Or it may backfire and somebody will 'disciple' him until he's back and committed again. Bad idea!
What exactly does he feel guilty about?
Is it that his KH friends miss him and the only time they would see him and catch up is at the meetings - he feels bad that they miss him? (I.e. he's hurting his friends.)*
Is it that meetings are communal worship and he feels he's missing out or shortchanging God by not going? (I.e. he's hurting God.)
Is it just a vague, 'superstitious' feeling that stems from having Heb. 10:24, 25 drilled into him for so long? (I.e. he's hurting the Org.)
Or a mix of all three?
If he identifies what, exactly, is triggering his guilt, you can both work on neutralizing it.
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* That's a pull with me. Recently two very nice JWs from our Hall dropped by after their FS. We get on with them, have some laughs, but they said they missed us and please come back - 'you know it's the Truth' etc. It was hard to keep our lips buttoned. While we were pleased to see them, naturally we do not want to have to sit through nearly 2 hours of irritation twice a week so that we can see each other. Nevertheless, the emotional tugs, the faint stirrings of guilt, did try to surface.