If they lose tonight it will be because the Astros are very good and we don't have the pitching, not because last night was something they can't recover from. And if they lose the series we'll look back on the fact that our two best pitchers provided no advantage (including in Game 6 possibly), more than the offense.
But right, now, we win the odd numbered games, so go do it! I'm definitely past the "it's all gravy" point though. Winning Game 1 on the road and taking a 2-1 lead both made the Phillies favorites in this series at the time, both for the gamblers and based on history. At this point it would be disappointing to lose.
I do think there's some psychological value in a getting a hit, just like there is sometimes value in scoring a couple of meaningless runs late. But it was a pretty cool piece of history: first post-season no-hitter since Roy in that same park, only second one ever in WS, and second combined Astros no-hitter with the same starter this season.