Scotland international McGinn believes Villa's 2-0 defeat against champions Liverpool should be a source of inspiration.
He said: “If we show the same character, desire and grit in the final five games then I'm sure we'll be fine.
“But it is important we show that and then when the chances come our way, we take them.
“The games just get bigger and bigger. It is up to us to puff our chests out and go and put in a similar performance, but this time get the result."
McGinn adds: “Just looking around in the dressing room, players are playing with confidence even though we're in this position.
“The break's been good for myself and others to get to match fitness and I feel a lot of us are showing that now.
“We're gaining a little bit of momentum, not results-wise but performance-wise, and hopefully we can use that going into what is an incredibly tough game against United."