Both the words 'mission' and 'ministry' come from the one Greek, New Testament word: 'service'. That great exemplary passage, Philippians 2, speaks of the example of Jesus Christ to us all, in emptying Himself, taking the form of a servant, humbling himself and being obedient. And calls us to do the same.
So here is a suggestion. Let's try just calling ourselves 'ministers', 'servants'. Let's stop examining our navels and whispering the question to the mirror, 'am I an apostle, prophet, evangelist, teacher or pastor?' Let me abandon self-affirmation and manifest such gifting as it pleases the Lord to manifest through me in service of others, in humility and submission to the collective discernment and decision of my peers.
Radical, eh? Or maybe just wise, as our forefathers thought when they called themselves but 'ministers of the Gospel'.