It sounds like this isn't a one time deal. You loan once, or gift, and what happens? Even if dad gets a job, he doesn't get paid for 2 weeks, maybe longer, how does he pay rent?

Are you going to give him enough for 2-3 months to get caught back up? 

This seems like a deal where it could get really, really bad, really, really quickly. 

If they've paid tithing, have the church pay for it. They've paid in, the church has enough, let them bless their lives.