Love God and do as you will, says St. Augustine, for love is its own commandment. That is how St. Francis took it and lived it.
He sinned, as all humans do, but after his conversion, he always knew when he had sinned because Love’s commandment drew him back to the divine love that underpinned everything he was and did.
It was not so much fear of punishment that motivated Francis but rather his commitment to him whom he loved, Jesus Christ. To separate oneself from Christ would be the sin for Francis.
If he feared anything, it would have been that he would betray Christ, the love of his life.
Love not for the reward, make love part of you.