The story goes that once, about a hundred years before Jesus’ time, a gentile wise-guy, put this proposition to Rabbi Shammai: ‘if you can teach me the Law, the Torah, while I stand on one leg I will become a Jew’. Rabbi Shammai, knowing a con when he hears one, sends him away with a flea in his ear. So the foreigner tries out his joke again, this time on Shammai’s rival, Rabbi Hillel. ‘Rabbi, if you can teach me the Torah while I stand on one leg I will become a Jew’. Hillel, always ready for a challenge, got him to stand on one leg and said, ‘That which is hateful to you, do not do to your neighbour. That is the whole Torah; the rest is commentary. Go and study it.’ And it is said that is what he did. … ‘That which is hateful to you, do not do to your neighbour’.
…
These two Rabbis were well known for their differences of opinion. Shammai taught that when it came to the shema—hear O Israel…—one should take scripture seriously and say it in the evening while lying down and in the morning recite it standing. Hillel’s opinion: recite shema doing whatever you are doing for it must fill your whole life, walking, sitting, working, playing: ‘Hear, O Israel: The LORD our God is one LORD; and you shall love the LORD your God with all your heart, and with all your soul, and with all your might.’
…
So we are to love God with our every breath—all our soul, mind and strength—and love our neighbour as ourselves. … But who is our neighbour? Don’t you want to follow Luke’s gospel and ask that? The scribe here in Mark seems to know already but Luke uses him as a foil to set up Jesus’ great parable of the prodigal son: an enigmatic answer to the question. Who is my neighbour and how do I love her? You’ll not be surprised to hear that Rabbi Hillel had something pithy to say on the subject: ‘If I am not for myself, who will be for me? If I am for myself alone, what good am I? … If not me, who? If not now, when?’
Aren’t those last two questions what ground and anchor our love for God and our love for others: ‘If not me, who? If not now, when?’