I think that 'broeder' is the older version of the word 'broer'. 'Broeder' is probably also used in churches. But I didn't grow up in a religious environment, so I'm not sure of that. And I've never consciously heard the word 'gebroeder'. It's a version of the word that isn't used that much anymore.

*Broer has the same maining as Brother in English *Broerder is like Martin said relaited to churche. It is a man, in the religion "Christen ". It is a person who devote their life for the religion. He lifes in a "monastery" with other broerders. I never heard gebroerder in Dutch.

Forget about broeder and gebroeder. I have never heard gebroeder. I think broeder is old dutch and not used in the normal spoken language.

oh sorry wrong place

Yes, 'broer' just means brother, and 'broeder' old-fashioned way to say it, or in a christian environment (just like the word 'zuster' for 'zus' (sister)), and sometimes it is used (for example rappers do this) to mean 'very good friend'. I have only heard the word 'gebroeders' in plural to name a couple of brothers, like 'de gebroeders Leeuwenhard' (the two brothers with name 'Leeuwenhard') or 'De gebroeders Karamazov' or 'De gebroeders Coen' (the Coen's Brothers) - and I think people still use this (although not very frequent)