How do you compel someone to do something joyfully?
Just so, by compulsion itself.
And the servant "who had been sent," brought answer, "Lord, it is done as Thou hast commanded, and yet there is room." "Go out," saith He," into the highways and hedges, and compel those whom thou shall find to come in." Whom thou shall find wait not till they choose to come, compel them to come in. I have prepared a great supper, a great house, I cannot suffer any place to be vacant in it. The Gentiles came from the streets and lanes: let the heretics come from the hedges, here they shall find peace. For those who make hedges, their object is to make divisions. Let them be drawn away from the hedges, let them be plucked up from among the thorns. They have stuck fast in the hedges, they are unwilling to be compelled. Let us come in, they says of our own good will. This is not the Lord's order, "Compel them," saith he, "to come in." Let compulsion be found outside, the will arise within. (St. Augustine, Homilies on the New Testament, 62.8)