" ... it denoted Christians eager to spread their faith in the existence of God, and of Christ as saviour."

Frankly, pete, I've always found that eagerness to be a bit alarming. When some 'eager' Christian approaches me in the street, or knocks on my door, to tell me the "good news!" about something or other, my instinct is to get away as fast as possible! If I ever found myself cornered by such a person, then there's a good chance that I might turn 'militant'.