After I recently claimed a tendency to be rebellious against others’ expectations of me, but not against God’s, someone I respect told me, “There is a difference between being radical and being rebellious!”
The dictionary defines radical as "of or going to the root or origin; fundamental". I imagine radical and eradicate come from the same root. It also means "thoroughgoing or extreme...favoring drastic political, economic, or social reforms." As a noun, a radical is someone "who holds or follows strong convictions...who advocates fundamental political, economic, and social reforms by direct and often uncompromising methods."
If we are talking about a radical follower of Jesus, I would translate this definition to indicate someone who holds strong convictions about what forms the heart of Christianity, and therefore works toward establishing that as the primary mission of the Church. And if we are getting right down to the root of Christianity, Jesus summed it up when He said, "'Love the Lord your God with all your heart and with all your soul and with all your strength and with all your mind'; and, 'Love your neighbor as yourself'" (Luke 10:27, NIV). Inherent in this kind of love as the mission of the Church is political, economic, and social reform. So yeah, I guess you could appropriately call Christians with a social reformation agenda - those who advocate for the poor and oppressed and marginalized - "radical".
I hope I can appropriately be called radical.
The same dictionary describes rebellious as "defying or resisting some established authority, government, or tradition; insubordinate". Militaristic movements against powerful, often oppressive majority parties sometimes get labeled as "rebellions". (For instance, take a look at the Boxer Rebellion, Shay's Rebellion, and the Whiskey Rebellion.)
It strikes me that the difference between radical and rebellious is that rebellion is an action to separate from or overthrow an existing system to bring about desired change. Radicalism seems to seek change within the system.
When it comes to the Church, I do not advocate anarchy (rebellion). However, I do believe sometimes reformation (radicalism) is necessary. And I believe this is a moment in the Church when a new Reformation is under way. History has shown us that sometimes people cannot come to agreement with respect to change - thus in the 16th century Reformation a third stream split from the Western (Roman Catholic) Church to form Protestantism. History has also shown us (through the Catholic Counterreformation that followed) that sometimes people can work out an agreement on change, and the whole system benefits from it.
"In all the work we do, our most valuable asset can be the attitude of self-examination. It is forgivable to make mistakes, but to stand fast behind a wall of self-righteousness and make the same mistake twice is not forgivable." --Dale E. Turner