What is the highest form of love?

Love is not love in the sense that you understand it if it is bestowed only on those who love you. 

The wider, bigger, true conception of that wonderful gift is in sending out love to those who seem outside its range altogether. And it can be done by prayer. By prayer and dedication, you can tear out those last roots of self—you can offer your mind, your will and your energies to the Father, saying from your very heart—

Use me in Thy service, for I, too, once was outcast from Thee.