prendre tout pour argent comptant ----> take everything at face value take something for granted -----> prendre quelque chose pour acquis

It is idiomatic and it is equivalent in English to : " Never take anything for granted "

Hi, Renan! "Prendre/accepter (quelque chose) pour argent comptant" is an expression that means "to believe naïvely (that something is true)". Another definition for this (in French): Prendre des dires pour vrais sans se poser de questions. (from https://fr.wiktionary.org/wiki/prendre_pour_argent_comptant) Example: "Dommage! Elle prend toujours les belles promesses de son mari comme argent comptant". In Portuguese, it would be something like: "Uma pena... Ela ainda acredita (cegamente, ingenuamente) nas promessas do seu marido".