The Musaf Shabbos Kodesh spoke with many important personalities who had known HaRav Moshe Shapira during his lifetime, and recorded their remarks. We are not capable of truly being maspid him as he deserves, but we have to do our best.
HaRav Boruch Dov Povarsky shlita, rosh yeshivas Ponovezh
We grew up in one house. This was originally in Tel Aviv, and again later in Bnei Brak. We were literally one home. I used to love to speak with R' Moshe zt"l because he was a genius and a gaon from his youth. We could speak about anything and he would understand and be incisive.
HaRav Moshe Shapira zt"l
I think that we can characterize him in a special way that we wanted to say in the hesped but did not get to it. The gemora in Sota says that when Rabbi Yochonon ben Zakai died it was the end of ziv hachochmoh. Rashi there says that he does not know what that is. And I say that in R' Moshe we saw what ziv hachochmoh is. There was chochmoh with Or Haganuz which is mentioned in the mishnah, through which one reaches the madreigoh of Rabbi Yochonon ben Zakai.
How did he grow to be so great in all areas of Torah?
Is says in Chazal: Yisroel, veOraissa veKudha Brich Hu are one. Is this understood?
This is a moshol in the medrash. The Torah is like a princess, whom all want to marry. She stands behind a curtain, and when they did not see her, many of her suitors left. Only one remained who waited for the curtain to move even a bit so that he could see even a little. When she saw this she said: You love the Torah so much, I will reveal to you all its secrets.
This was the greatness of Rabbi Moshe. Aside from his great power and wisdom, he truly loved the Torah. He looked for it all the time, more and more Torah, his love was without bounds. When he started to learn Kabboloh, he did not give up until he mastered it without any limits. Once when I asked him about a passage in the Zohar, he answered me right away, a complete answer.