Fanaticism obliterates the feelings of humanity.
How many of us have conflicts with someone else- and how many of us pray for that person? We have individuals with whom we are competitive, or whom we dislike or have a quarrel with; but very few of us have true enemies in the martial sense. And yet if Lincoln could pray fervently- and contemporary reports indicate he did- for the people who were opposing him, how much more can we do for someone we just find a little irritating?
Perhaps all the questions we ask of love, to measure, test, probe, and save it, have the additional effect of cutting it short. Perhaps the reason we are unable to love is that we yearn to be loved, that is, we demand something (love) from our partner instead of delivering ourselves up to him demand-free and asking for nothing but his company.