"The missionary is urged on by “zeal for souls,” a zeal inspired by Christ's own charity, which takes the form of concern, tenderness, compassion, openness, availability and interest in people's problems" (Para.
The driving force behind a missionary's actions is their fervent desire to bring people closer to Christ, which is rooted in His own compassionate nature, expressed through kindness, understanding, warmth, openness, and a genuine concern for the well-being of others.