Yishai made the remark a day after apologizing for allegedly saying that the Second Lebanon War ended the way it did because soldiers failed to pray.
Speaking at the Or David rabbinical institution in Bnei Brak, Yishai argued that the Jewish people survived over the years only thanks to their religious faith.
"Maimonides says that those who don't believe the people of Israel exist more than nature are atheists," Yishai was quoted as saying by ultra-Orthodox website Kikar Hashabat.
"For thousands of years, even before the State's establishment, each person was somewhere else in the world – without a country, without an army, without the Shin Bet, without anything.
"The Jewish people survived the 2,000 years since the Temple's destruction to this day only thanks to the Torah, which protected the people of Israel. The people of Israel would not have existed without the Torah."
The minister claimed that Israel's leaders consulted with Rabbi Yosef and followed his advice. "There are many stories which I cannot reveal, very complex consultations. What our master, teacher and rabbi said and they did – was a great success.
"And how does our master, teacher and rabbi know what things to say? It all comes from Torah studies. The prime minister and respected ministers come to listen to what the rabbi has to say – and he wasn't in the Military Intelligence, Shin Bet or Mossad and is unfamiliar with all the secret and sensitive internal discussions.
"But at the end of the day, they all come to listen to him, the outstanding rabbi of the generation who studies Torah and who has not been responsible for any failures."