I think we have people that are not even leaving their comfort zone to engage people with the gospel. I don't know if you can be overzealous, but you can be unwise in the way you do it.
Is it possible to be overzealous, to destroy that which you hope to save-so that nothing is left but emptiness.
You might be a legend one day if you just keep your head to the ground and never get overzealous and start thinking you've outdone yourself. That's the space I try to stay in.