At current interest rates, that's about 3,800 after taxes and insurance, according to a quick internet search. Another quick search says that $90,000 in gross income is a take home pay of roughly $66,000, or $5,500 a month.

So if the young family can live on $700 a month, save $1,000 for a down payment every month, they should be able to afford the down payment in about nine years. Oh, crap, I forgot about tithing on that $90,000. Back to the calculator.

Of course you could start at a cheaper home, get a loan from parents, take on another job, maybe have one of the two with a higher paying career, etc. But any way you look at it, the math is quite challenging, and significantly worse than just five or ten years ago.