the sign of the true grace of God is a desire to live righteously, and to remain in Love and truth. Grace is the cause, but Holiness and Love and truth are the effect.\
Grace is not the cause of anything.
Grace is the act of recognizing our sincere, if imperfect, keeping of the covenant as the ‘garment’ for the wedding feast.
There is not one word in the entirety of scripture that indicates that it is anything else. Grace doesn’t save; it allows us to be saved through faith. That is what the word of Yehova says.