I have four sons whom I love dearly. Suppose our lawn needed to be cut. I could say, "Boys, can you see the need? The grass is high. It's above my knees. Soon I will not be able to get to the garage. Don't you see the desperate need?" But in the final analysis, they get out the mower because their father says, "Mow the grass!" World evangelization is an imperative because Jesus said so.