Parshat Nitzavim

Devarim 30:1-3
When all these things befall you — the blessing and the curse that I have set before you — and you take them to heart amidst the various nations to which the LORD your God has banished you, and you return to the LORD your God, and you and your children heed His command with all your heart and soul, just as I enjoin upon you this day, then the LORD your God will restore your fortunes and take you back in love.
Devarim 30:11-19
Surely, this Instruction which I enjoin upon you this day is not too baffling for you, nor is it beyond reach. It is not in the heavens, that you should say, “Who among us can go up to the heavens and get it for us and impart it to us, that we may observe it?” Neither is it beyond the sea, that you should say, “Who among us can cross to the other side of the sea and get it for us and impart it to us, that we may observe it.” No, the thing is very close to you, in your mouth and in your heart, to observe it. See, I set before you this day life and prosperity, death and adversity. … I have put before you life and death, blessing and curse. Choose life …
Rabbi Adin Steinsaltz
here [in this parsha] there is also the way of teshuva.
Peskita DeRabbi Kahana 24:7 (translated by Adin Steinsaltz)
Wisdom was asked: What should be the sinner’s punishment? Wisdom answered: “Evil pursues sinners” (Prov 13:21). Prophecy was asked: What should be the sinner’s punishment? “The soul who sins shall die” (Ezek. 18:4). The Torah was asked: What should be the sinner’s punishment? The Torah answered: “Let him bring a guilt offering, and his sin shall be atoned for.” The Holy One, Blessed Be He, was asked: What should be the sinner’s punishment? He answered: “Let him do teshuva, and his sin will be atoned for.” 
Rabbi Adin Steinsaltz
The Torah speaks of choosing the good, and advises us to choose life. However, when one must implement the choice in reality, it is not always clear which path to choose; distinguishing the blessing from the curse is not always simple. If the reality were clear to us, we would not commit so many errors. 
Sometimes one makes a decision based on his perception of reality, and afterward — even if it becomes clear that the decision was made on the basis of mistaken assumptions — he can no longer withdraw the decision that he made. One chooses what he thinks is a blessing, and he ends up being totally subservient to it, even though it has already become a curse for him.
In other instances, the question whether something is a blessing or a curse is completely subjective. For one person it could be a curse, but for someone else it could be a blessing. It could be that now it is a curse, but at another time it will be a blessing.
Thus, the choice between blessing and curse is partly subjective: How does one regard the events that transpire in one’s life? … It often happens that it is the individual who decides whether it is a blessing or a curse; it is not a matter of knowing the future. If one decides to accept something as a curse, it will only grow worse, while if one decides to accept it as a blessing, it will fulfill that initial perception.
the entire Torah can be considered a blessing or a curse. We have 613 mitzvot; this might seem like a huge number — who can meet so many requirements? This perspective turns the whole Torah into a curse. However, an alternative perspective is found in the Mishna: “The  Holy One, Blessed Be He, wanted to give Israel merit; He therefore gave them a large amount of Torah and mitzvot” (Makkot 3:16)
Blessing and curse do not necessarily exist in two separate worlds; sometimes they are in the same place. The Talmud states that the tzaddikim in Paradise sit and enjoy the splendor of the Shekhina (Berakhot 17a). In Paradise, there is no eating or drinking, only enjoyment of the Torah. There are people who deserve to be sent to Gehenna, but should really be sent to Paradise. For some people, an eternity of constant Torah study would be the greatest form of torture.
To choose life is to see things from the right perspective, to choose the good aspect in everything. … “Choose life,” therefore, relates not only to the choice itself, but also to the manner in which one chooses.