“In the beginning, God created…” Rashi says, Rebbe Yitzchak said, “It wasn’t necessary to begin the Torah from any point before ‘This Month,’ which is the first mitzvah, etc., rather He started with the story of Creation in order to divulge the power of His deeds to His nation and to thereby give them the inheritance of other nations, so that the nations of the world would not say, ‘You are thieves, etc.’” Well truly, what is the big deal if the other nations say this or that, what does it matter to me? Would I really change the order of the Torah just for that? Furthermore, what does this big declaration do, starting with Creation, what would it matter as anyways the nations of the world do not believe in anything written in the Torah, and deny its divinity? If there are, to our great dismay, such deniers among the Jews, who say there is no Law and no Judge, all the more so among the gentiles! If so, regardless they would say, “You are thieves!”
Regarding the mitzvah of bringing the first fruits to Yerushalayim, the Torah wrote a long paragraph that he who brings the fruits must recite (פרשת כי תבא). It begins with “My father was a wandering Aramean” and continues to retell the events, hardships, and trials that our forefathers navigated until Hashem “brought us to this good land, a land flowing with milk and honey, etc.” The root of and reason for this mitzvah is, according to Sefer Hachinuch, the Rambam, and others, is that just as Hashem does good for us and blesses us and His land until we merit to bring fruits to the House of Our Lord, etc., it would be appropriate for us to arouse our hearts and realize that everything came from the Master of the Universe, and this would lead to submission and subjugation to Hashem. Because it is possible that after settling and inheriting the land, after reaching the final destination and living in the land in peace and tranquility, that they would forget that it was only through the kindness of Hashem that all of it came to fruition, and that He, the Master of the Universe, gave them strength and victory. And they would be boastful and say that it was by their own military power that they succeeded in conquering the land, and that it was by their own strength and by the power of their own hands that they achieved such great feats , and not by the hand of He who we must listen to His voice to keep the Torah and mitzvot.
Truly the holy land was not give to us on anything but the condition and merit of keeping the Torah and fulling the commandments- therefore, God commanded us to bring the first fruits year after year, to lift the basket on our shoulders and stand before Hashem to testify and declare the unending kindnesses of Hashem, and that power and strength is not ours, rather everything is Yours and from Your hand was given to us. For it was in small numbers that our forefathers descended to Egypt, they tortured us with hard labor, subjugated us, and embittered our lives with various methods of torture. All this until Hashem had mercy on us and brought us out from there with a mighty hand, fed and sustained us forty years in the desert, and brought us to this place, displacing larger and stronger nations to give us their land as an inheritance. So, if they declare this year after year, they will consequently fully recognize that only the hand of Hashem did all this, and only because Hashem is here- everything is here, and by retelling the events and trials that befell our forefathers, our faith would be aroused and strengthened to love Hashem and keep his mitzvot.
Therefore, it is for this reason that the Torah opened with creation. Granted the true essence of the Torah is the mitzvot, and that the whole world was created for the Torah, such that the Torah should start from the first mitzvah of sanctifying the new month, and everything written prior is just the story of creation and the goings-on which befell our forefathers all those years. However, keeping the Torah and mitzvot depends and stands on these stories of our forefathers. Just as bringing the first fruits raises the memories of Hashem’s kindnesses performed, bringing us under the wings of the Shechina, and through this we will accept the yolk of His Kingship and Torah, so we should not say that our strength and power did all these great things. Just as we are obligated in the Torah, Mitzvot, and faith in Hashem, we also need to know what happened to our forefathers (including their behaviors and way of life) from the creation and onward. This is so we will know the path to walk on and the deeds we should do. This is what is meant by the phrase “The power of His deeds he divulged to His Nation.” Hashem tells over, and reiterates over and over, the power of His deeds- how he created the world, how he dealt benevolently with our forefathers until they reached the Land of Canaan, and how much they suffered throughout those years- in order to give us the inheritance of the other nations which was His original intention. The intention was to give them the land of the seven bigger and stronger nations, so that they should not err and hang their success on their own strength and determination in battle, saying ”Who is Hashem that we should listen to His voice?” and be like all other nations. After all, Hashem gave them the land of other nations only so that they would keep the Torah. Therefore, Hashem prefaced all the mitzvot with the story of Creation: because one is dependent on the other. If, heaven forbid, they would not believe in the Creator, in He Who Alone Performs Incredible Wonders, they would not keep the Torah and the Mitzvot as well; therefore, the Torah starts from Creation.