The Scotland international said the players had to look within themselves following the 3-0 defeat to Liverpool on December 30 and have responded well since then.
When asked what had sparked an upturn in results, Mackie said: "Probably a bit of soul-searching for yourself and looking at yourself.
"Going home and looking at yourself in the mirror and saying 'I've given everything' and the lads have done that now. No-one can say the lads haven't done that in the last two league games.
"That is what it is going to take for us to get out of it because we have definitely got quality if we work from a good platform."