Our Sidra gives some of the specific guidelines that help engender a society led by good leaders with good law by pointing out what we expect of leadership and law. Our lives are meant to replicate the characteristics of G-d. To be compassionate, to be loving, to be kind, to be unswerving in the reach for good and to be uncompromising in distancing ourselves from bad. This is pointed out by the Chatam Sofer who notes on the verse in Vayikra, that there are two sorts of separation - that of Chanoch ben Yered and that of Abraham. Even though they might show the same signs and wonders as previous prophets if anyone be they prophets or kin, calls on us to leave aside our laws and traditions we must remove this evil from amongst us.
Moral laxness is an unbearable burden on society.
We must guard ourselves, our heritage and tradition from perversion. It is all too easy to lose identity and to lose ability to discern between that which is good and that which is not by paying attention. We must always walk forward as standing still is a regression itself. The repetition of the Mitzvah of not adding or subtracting from the Torah is understood by the Vilna Gaon as not just referring to accepting new or discarding old Mitzvot but also the specifics of a Mitzvah. G-d's Guidebook to his people is complete, it is applicable to today's world and we should go after Him and fear Him, keep the Mitzvot, listen to His voice, serve Him and cleave to Him.