"We have to be honest about what went wrong, but we also have to be calm," Luiz told Sky Sports.
"It's only our second defeat this season. We are doing many things well. We have to keep believing in our philosophy, we have to keep believing in our team, which is the best way for us to improve.
"Football is about the end, not the beginning, so let's see how we finish at the end of the season in May. We have to win, we always have to win.
"If you want to achieve big goals, you have to think about winning, winning, winning. It'll be tough against Crystal Palace but we want the three points. I want to win titles with Arsenal, that's why I'm here."
Arsenal star David Luiz sends stern message to team-mates over Unai Emery tactics (Image: GETTY)
Arsenal star David Luiz sends stern message to team-mates over Unai Emery tactics (Image: GETTY)
Arsenal star David Luiz sends stern message to team-mates over Unai Emery tactics (Image: GETTY)
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Arsenal did earn victory in the Europa League in midweek as a late Nicolas Pepe free-kick ensured they beat Vitoria.
But Emery was concerned with the way his side went about the win.
He said: "We struggled more in the first half than we wanted. We lost a lot of balls in midfield and gave them chances in the transition to score and to start winning the game.
"In the second half, I think we controlled it better. We created chances but our attack was playing more with their emotion and heart tonight than with control, or with shape on the pitch. We weren't as organised in the attack."