This week, two sections of the Torah are read: Nitzavim and Vaielech (firm and was, respectively). One of the main themes that appears in Parashat Nitzavim is the concept of free will, along with that of reward and punishment.
The Torah says (Deuteronomy 30:19): "I call heaven and earth to witness against you today that I have set before you life and death, blessings and curses. Now choose life, so that you and your descendants may live." The verse clearly indicates that God gives us two options: that which is life, which is a blessing (which consists of observing the commandments, as the previous verses state), and that which is death and a curse (which consists of abandoning the path of Torah and clinging to idolatry, even in its most subtle forms, such as the idolatry of money or physical beauty).
However, what's not so easy to understand is the continuation of the verse, where it says, "and you must choose life": Is there anyone (healthy) who would choose the opposite of life? Why does God have to come and "advise" us to choose life?
The question becomes even more compelling according to Rashi's commentary on these words, which goes something like this: "I (God) instruct you to choose the portion of life, like a man who says to his son, 'Choose for yourself a good portion from my inheritance,' and leads him to the best portion and says, 'Choose this for yourself.' Regarding this, it is written (Psalms 16:5), 'God is my portion, You hold my portion,' You placed my hand upon the good portion, saying, 'Take this for yourself.'" Clearly, Rashi understands the Divine command to choose life as if God Himself were guiding us and placing us before what is good, and, so to speak, putting our hand upon the best so that we simply take it. Then, would anyone even consider taking anything else?
To understand this, we must first grasp the concept of free will. The ability to choose our own future is based on the premise that the options we have to choose from must be equal; otherwise, it's not a true choice. When we have a good apple and a rotten one in front of us (and we want to eat the apple), we can't choose; we're forced by an external factor to take the good apple. Similarly, there are internal factors within each person (for example, prejudices and habits) that "force" them to make certain decisions, even if those decisions appear to have been freely made.
In the case of Torah and Mitzvot, although God clearly states that they are life and blessing, if this were something visible and easily recognizable, we would not be able to choose to study Torah and fulfill Mitzvot instead of the opposite, since we would see the opposite as death and a curse. Therefore, God conceals how good Torah and Mitzvot are and makes them appear equal to their opposites, so that we can truly choose between one and the other.
Here is the reason why God must indicate to us in such detail (as Rashi says, "He takes him to the best portion and says to him: 'This one chooses for you,' You placed my hand on the good part, saying 'This one takes for you'") that we should choose life: at first glance it seems that a life with Torah is the same as one without Torah, but in reality, it is not, and this is indicated by the Torah saying "and you shall choose life.".
May they be registered and sealed for a good and sweet year,