Перевод - Датский-Французский - At kæmpe for det man tror pÃ¥ kan tage tid.

Sorry?? I kindly ask you to recheck the translation, please ;-)

Hi Minny!

"ce en quoi" (eg : "ce en quoi nous croyons" ), "ce pour quoi" (eg : "ce pour quoi nous luttons" ), "ce vers quoi" (eg : ce vers quoi nous tendons" ), "ce par quoi ( eg : "ce par quoi nous vivons" ), all these are correct and usual in French, if it is what you were in doubt about

Thank you so much for kind explanation. (Sorry, I thought that you had forgotten to delete a word or two). May I ask you if the following is also correct: "Lutter pour c'en quoi on croit peut durer longtemps." "Se battre pour ses convictions peut prendre du temps."
Thank you so much in advance for your time and efford! ;-)

You're welcome, dear Minny!

"c'en quoi" is not correct, while "ce en quoi" is correct. ("ce" and "en" don't sound the same, and "c'en quoi" would be ressembling "sans quoi" too much, which has a different meaning)

"Se battre pour ses convictions peut prendre du temps" is perfect!

Thank you so much, dear Francky, I have leant a lot! ;-)