A slick finish from Lee Tomlin fired Posh ahead against their fellow Championship strugglers, and it took a second-half penalty from DJ Campbell to secure Town a point.
Ferguson said afterwards: "I feel there's a great trust between myself and the players. We've got character in abundance and there's no question of us failing on that front.
"We just have to stick together and see it through. If we do that, and play like we did today, we've got more than enough time to turn it round and get out of it.
"I'm disappointed we didn't get three points and thought it was a missed opportunity.
"We just couldn't get a second goal and that was our biggest frustration. There were still a lot of positives to take from it, though.
"We look a lot more solid with three at the back, took early control of the game and I didn't think we were in any danger until the penalty.
"Then towards the end we had two or three good chances to win it. I knew we'd get chances on the counter-attack.
"They've conceded 14 goals in the last 15 minutes and I thought this might be another opportunity to get another late one."