The Gunners host in-form Swansea City on Saturday, when Michael Laudrup's side will aim to protect a five-game unbeaten run and build on their midweek win over high-flying West Bromwich Albion.
It is the first of eight December games in all competitions for Arsenal, who play West Brom, Reading, Wigan Athletic, West Ham United and Newcastle United in the Premier League as they seek to return to the top four.
Arsene Wenger's side also travel to Olympiakos in the UEFA Champions League, where they have already qualified for the knockout stages but need a win to stand a chance of finishing in the important top spot of their group, and visit Bradford City in the Capital One Cup quarter-finals.
And in the wake of Wednesday's draw at Everton, Mertesacker wants a win against Swansea to set the right tone, as he said: "Swansea are a good, technical side - they can play shorter and longer balls to good effect.
"But we have to look at our game first and improve on the Everton performance. We have to respect our game as well as that of the opponent.
"December is here, and it's a very important month for us - let's start it as we mean to go on."
Meeting Swansea again will bring back happy memories for Mertesacker after the German international made his Arsenal debut against the same opposition in September 2011.
The £8million signing from Werder Bremen said: "My first game last year was against Swansea, so it's always something special to face them.
"They are playing well - they have good possession and are doing similarly to last year, when they were impressive.
"It's important that we keep to our normal game plan and be ready to do something right from the start, especially in the final third of the pitch.
"We want to get the three points. The league is getting harder every year and every opponent is getting better, so we need to keep concentrating and show exactly what we can do."