The Gunners consolidated top spot in the Barclays Premier table by securing a 2-0 win at managerless Crystal Palace, where captain Mikel Arteta was sent off not long after scoring a penalty at the start of the second half.
Arsenal boss Arsene Wenger felt his team had given the needed response when questions had been asked in the wake of the midweek Champions League home defeat by Borussia Dortmund.
Chelsea head to the Emirates Stadium on Tuesday night for a Capital One Cup tie when both sides are expected to rotate their teams, before Arsenal host second-placed Liverpool next weekend and then head out to Dortmund, where defeat would leave serious doubts over qualification for the knockout stages.
Throw in a trip to Old Trafford and then the visit of surprise package Southampton, all before the end of November, and the need for consistency soon becomes clear.
"Palace was a good test for us and a good win ahead of the hard games to come in the next weeks," Mertesacker said.
"We wanted to come back quickly as possible as a strong unit.
"What we showed was good enough to respond here (against Palace), but there will be more tests to come and that will be crucial for the rest of the season.
"That we have started well showed for sure we have improved a lot over the last two years.
"We are in a better position. It feels much better now. We don't have to get anything back (on the other sides), so that gives us more safety and we feel much better."
Mertesacker added: "We want to surprise people more and more. That is what we need to do.
"We are in a strong and interesting position, so we are aware of it and will try to keep it - but that is the difficult thing, to keep it."
Germany defender Mertesacker - whose partnership with Laurent Koscielny is keeping club captain Thomas Vermaelen on the bench -feels Arsenal's continuity and the addition of players such as Mesut Ozil and Mathieu Flamini has allowed them to hit the ground running.
"It took us a lot of time to settle in and adapt for a lot of players, but we did not lose anyone this season and I think that is a big advantage," added Mertesacker, who was one of several players signed on deadline day in August 2011.
"Everybody knows each other, how to cover each other, we have a much stronger squad."
Wenger believes a united work ethic has been behind his team's consistency in the Premier League, where they have lost just once and that back on the opening day.
"It is a good sign because it shows that the team can win when we are not completely flying," the Arsenal boss said. "We decided to work hard, especially defensively.
"Even until the end, Ozil fought very hard, played on the right, played like a full-back. It is good to see that everybody puts a shift in when it is needed."
Wenger accepts Arsenal will know more about what they can achieve after the toughest of November schedules.
"We have drawn only once and won all our other away games and we have more points ahead of everyone else, so that is not bad," he said.
"However, the disadvantage is that some teams have had heavier fixtures than we have had until now, and that is what is facing us."