Today's Gospel reading is chock full of things Jesus said that we know He didn't really mean, like this:
If you bring your gift to the altar, and there recall that your brother has anything against you, leave your gift there at the altar, go first and be reconciled with your brother, and then come and offer your gift.
What Jesus neglects in this passage is the very real possibility that we're perfectly all right with being unreconciled with our brother, who is, let's face it, a fool.
Besides, isn't the whole "bring your gift to the altar" business a bit OBE? The gift we bring to the altar is Christ Himself, and He is the priest Who offers it. We're there mostly to be sort of sucked into heaven in His wake.
God wasn't exactly pleased by imperfect offerings back in the day, but if He really expected us to be perfect, He'd have told us to be perfect. Perfection is for saints (and maybe really old people).