Does marrying a German person & having a German passport makes you a German?

Hello guys, So a pal that’s a German wife, and owns a German passport was discriminated and denied entry into a party although he was on the VIP GUEST LIST.. This friend got a German passport but he’s originally from Nigeria. Now my question is, Does having a German passport makes him an African-German?, will people stop seeing and treating him differently (As they treat Africans)?.. Maybe you have experienced such thing before ?.please share with with me.