Created TO DO
The commandment of circumcision (Brit Milah) that Abraham Avinu fulfilled in Parashat Lech lecha, appears for the second time in Parashat Tazri'a. But the context is completely different to that of Parashat Lech Lecha. The circumcision mitzvah is mentioned in relation to the impurity of the parturient (Tumat Ha-Yoledet).
"And G-d spoke unto Moses, saying: Speak unto the children of Israel, saying: If a woman be delivered, and bear a man-child, then she shall be unclean seven days; as in the days of the impurity of her sickness shall she be unclean. And in the eighth day the flesh of his foreskin shall be circumcised" (Leviticus 12:1-3).
There is a well known dialogue between the wicked Turnusrufus and Rabbi Akiva which will help us in understanding the deep meaning of the commandment of Brit Milah:
"Whose deeds are more pleasant -asked Turnusrufus to Rabbi Akiva- those of G-d or those of flesh-and- blood?'.
He replied: "Those of mortals".
Asked Turnusrufus: "What about heaven and earth? Can man create the likes of those?".
"Said R' Akiva: 'Don't tell me things that are beyond the capacity of mankind, things they are incapable of. Give me an example that they can accomplish as mortals".
"He asked: 'Why do you circumcise yourselves?'.
"I knew you would ask that. That's why I started off by saying that man's actions are better than G-d's.' He then brought some wheat stalks and some pastries and said: "These are the products of G-d and those are manmade products. Aren't those [cakes] better than these stalks?".
"Said Turnusrufus: 'But if He desired circumcision, why doesn't the newborn emerge from the womb already circumcised?".
"Said R' Akiva: '…This is because G-d specifically provided us with commandments in order to purify us through them…" (Tanchuma Tazria).
What does the Midrash want to teach us?
Turnusrufus represents the opinion of all those who believe that in nature all is perfect and as such no amendments should be carried out. If the Creator is perfect – suggests Turnusrufus – also the Creation should be perfect and there is no sense that mankind will come and fix something that does not need any fixing as it is perfect!
The RaMbaM says at the beginning of Hilchot Avodat Kochavim (1, 1):
"In the days of Enosh, the people fell into gross error, and the counsel of the wise men of the generation became foolish. Enosh himself was among those who erred. Their error was as follows: ‘Since, God,’ they said, ‘created these stars and spheres to guide the world, set them on high and allotted to them honor, and since they are ministers who minister before Him, they deserve to be praised and glorified, and honor should be rendered them; and it is the will of G-d, blessed be He.
Enosh saw that the world was doing OK and this led him to the wrong conclusion that nature (and in his case the stars) are worth worshiping.
Enosh's mistake was similar to Turnusrufus' and their opinion seems to be a pagan concept: "If G-d is perfect so the world must be perfect as well".
Abraham Avinu, says the Rambam (Hilchot Avodat Kochavim 1, 3), saw the same things that Enosh saw but he reached a different conclusion: he understood that the nature phenomena has a leader and only the leader (and not nature!) is worthy worshiping.
Natural things not necessarily are perfect. Rabi Akiva thinks that there is a place for mankind to intervene in nature.
When we read about the Creation it is said: ."And God blessed the seventh day, and hallowed it; because that in it He rested from all his work which he created TO DO" (Genesis 2:3).
Why it is written TO DO?
Because the Creation needs mankind intervention. G-d created the world in order TO DO so that we will be able to complete its creation…because the world is not perfect.