A teaching from Menahem Nahum of Chernobyl, Meor Einayim.
At the beginning of our morning prayers we say, “I accept upon myself the mitzvah to love your neighbor as yourself,” because really we are all one. Just as the Torah, should it be missing a single letter, would no longer be the Torah, so we cannot we be without each of us, for “everyone has his or her own letter in the Torah.” So even if you see something bad in your fellow, hate only the bad, but your fellow you should love as deeply as your own soul, for just like you he is a part of God.
The Baal Shem Tov taught that a purely righteous person sees no wrong in anyone else. For looking at another person is like looking into a mirror: if your face is dirty, you see a dirty face, but if your face is clean, you see only a clean face. So if you see something wrong in another you are actually seeing the wrong in yourself. Just as you still love yourself even though you see your own flaws, so should you continue to love your fellow, flaws and all, for in truth everything is one.
The sages say that the Second Temple was destroyed because of baseless hatred, and so the natural path to redemption is unconditional love. May we all use this day as a chance to learn a little better how to love one another.