Old French gentil, jentil, etc. high-born, noble (modern French gentil elegant. Spanish gentil , Italian gentile < Latin gentīlis belonging to the same gens or race, < genti- , gens race, family. The sense ‘belonging to a good family’ common to the Romance tongues is not found in Latin.
Gentleness is one of the "fruits of the spirit" or defining noble characteristics of a Christian found in Galatians 5:22-23 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law"