The Ponevezher Rav z"tl after the Shoah, started Yeshivos for the many orphans and called them Batei Avos as he was looking to raise a new generation of fathers. Once, when visiting the boys, he asked if anyone knew a reason for the custom of reciting at the end of Shemoneh Esrei a verse from Tanach wherein the opening letter of the verse is the first letter of one's name, and the last letter of the verse is the last letter of one's name[1]. The Ponevezher Rav z"tl suggested the following answer:
After 120 years when one is brought before the Divine throne of glory, one is going to forget their name. The fright is so great, as Abba Kohen Bardela taught (Bereishis Rabbah 93:10) that just as the brothers could not answer Yosef (Bereishis 45:3) because they were shocked to find that it was him before them, even more so when one will have to answer to Hashem he will not be able to reply. The Ponevezher Rav explained that the one thing you do take with you to the next world is the Torah and mitzvos that one studied and performed in this world. The recitation of one's name thrice daily in a passuk will accompany that individual (since reciting the passuk constitutes an act of learning Torah) and will remind him of his name.
The concept that one's spiritual wealth that they amassed in one's lifetime is the only possession one takes to the next world is found explicitly in Parshas Nasso according to the Chofetz Chaim. The Torah states, "ish es kadashav lo yehiyeh - a man's holies shall be his, what a person gives to the Kohen shall be his" (Bamidbar 5:10.) All of one's material acquisitions are by nature transient and temporary, as the saying goes: there are no pockets in tachrichim (burial shrouds.)
This is found clearly in Talmud (Bava Basra 11a) regarding King Munbaz, who according to Rashi was the son of Queen Helena, one of the Hasmonean Kings. We are taught that during years of famine he opened his storehouses and treasuries and supported the poor. He was severely criticized by family members because unlike the royalty before him that added to the family fortune, he was depleting the family fortune. He answered with three points: 1. My fathers hoarded wealth below, on Earth, while I have hoarded wealth above, in Heaven 2. My family gathered wealth in an insecure place, and I have accumulated wealth in a most secure environment 3. My forefathers stored something that does not produce fruits, but I have hoarded something that does produce fruit.
Moreover, this concept is explicitly taught in Avos (6:9) by Reb Yosi ben Kismah in explaining why he refused a lucrative rabbinic position in a not yet religious community. As part of his rejection, he explained that, "when a man departs from this world, neither silver, nor gold, nor precious stones, nor pearls escort him, but only Torah study, and good deeds, as it is said, (Proverbs 6:22) 'when you walk it shall guide you, when you lie down, it shall guard you, and when you are awake, it shall speak on your behalf.' When you walk it shall guide you in this world, when you lie down it shall guard you in the grave, and when you awake it shall speak on your behalf in the world to come."
The Chofetz Chaim zt"l presented the following parable in the name of our Sages: a man had 3 friends, the first he was closest with, loved him, and thought the feelings were mutual. The second he also considered close, but not like the first. The third he had associations with, but not as strong as his connections to the others. One day the man was summoned suddenly to the king. He was not told the reason for his urgent appearance before the king, but he was exceedingly frightened to go alone. He asked his first and closest friend to accompany him and to his great surprise, he was refused. The second closest friend agreed to go, but only to the palace gates. In desperation he approached the third friend, and much to his surprise he not only agreed willingly and cheerfully to accompany him to the king but agreed to vouch for and present a most complimentary presentation on his behalf before the king.
The meaning of the above is obvious. The fortune and all material possessions that one invests time and effort amassing are too often that first friend - they flatly refuse to accompany a person to the next world. The second friend is representative of one's family - they tearfully can only accompany a person until the grave. However, that last friend, whom he did not realize how loyal he is, is his Torah study, mitzvos, and good deeds, which excitedly accompany you and endorse on your behalf.
Finally, I'd like to suggest that this is further communicated by King David, (Tehillilm 139:5), "achor vakedem tzartani - back and front have you formed me." The Radak understands kedem - back, to refer to the formation of the embryo in the mother's womb. The Talmud (Niddah 30b) teaches that the baby in utero is taught Torah. The neshama of man is surrounded by Torah prior to birth, and the many sources cited above affirm that the soul is protected by Torah in the next world. It is thus understood that the Talmud (Pesachim 54a) lists Torah as the first of the seven supernatural phenomena created prior to this world, as it truly is beyond this world in every sense of the word.
[1] This practice is found in Sefer Ha'Kavanot Ha'ari, it is said to be helpful in preventing chibut ha'kever, is attributed to the Kitzur Shelah, and is found in the Aruch HaShulchan (Orach Chaim 122:8).