Honor in MCSG is honestly one simple act, proved through numerous different acts. That act is respect, one of the, if not the most important custom in MCSG.
There's numerous ways you can show this in MCSG, whether it's through following and respecting rules, respecting players, and staff, or just respecting the game itself-- respect is the key to having honor in MCSG.
It's so important because if you can't respect other players, and staff, the rules, or the game itself and how it's played, how can you even play MCSG?
Respect for the rules is an obviously important aspect, because if you don't, you'll spend your time at MCSG getting in trouble, and being kicked, or banned.
Respect for the game itself is also ridiculously important (these all are). If you don't respect the game, or how it's played, you'll play every game in loath, or hate, whi h obviously won't keep you around for a very long time.
Respecting other players and staff is something every player should know to do, as well. If you can't respect the people around you, in the same community, it'll bring you to hate the game, more or less.
With or without that rather drawn out explanation, honor in MCSG is honestly respect. Part of being a player in MCSG is being respected by fellow players, and respect is not something you can receive without first giving.