How so? Southern Europe is very relaxed in this sense culturally, and it's the most religiously Christian part of Europe at the same time. While atheist northern and central Europe (Germany, Netherlands, Scandinavia, Switzerland) place a lot of emphasis on reliability.
Sure you could argue that these nations are culturally Christian, but Christian culture still doesn't imply an emphasis on reliability.
At most I might agree with this being a case of the protestant work ethic, which seems to have a high correlation here (northern and central Europe as well as America is very much protestant, southern Europe is more catholic and orthodox).
However first of all most historians agree it's false, and second you get places like Germany, where the economic powerhouse is the catholic south (Baden-Württemberg has Porsche, Daimler (Mercedes), Audi and Bosch, Bayern (Bavaria) has BMW, the protestant North and East are more poor).