It says that the 3rd Beis HaMikdash will exceed in grandeur and glory the 2nd Beis HaMikdash , which turn was grander than the 1st.
Not only that, the first two Temples stood for 410 and 420 years, respectively, whereas the 3rd Beis Hamikdash will last forever.
The Chazal say in reference to Avrohom Avinu that he is compared to a mountain, Yitzchak is compared to a field, and Yaakov is compared to a house. The 3rd Beis HaMikdash is connected specifically to Yaakov, as is explained in Likutei Torah, Yaakov’s mida is Emes and with respect to Emes – Truth, interruption or cessation doesn’t apply, therefore the 3rd Beis HaMikdash will be everlasting.
Additionally, the are three redemptions, the 3rd redemption is connected with the 3rd Beis HaMikdash, this third redemption will take place after it’s been built. More specifically, the main characteristic of the 3rd Beis HaMikdash will be Tchias HaMeisim –the Resurrection of the Dead after which there will be eternal life.
It’s known that the avoda of tzaddikim deals with the Ishtalshilus whereas the avoda of Baalei Tshuva reaches above Ishtalshilus. As is written “in the month of Ariel, there rose up Ariel and destroyed Arile (Beis HaMikdash) on the condition that it be rebuilt by Ariel”
It’s written that after the exiles returned from Babylon and rebuilt the Temple (2nd ) there was a possibility that it could become the ultimate Beis Hamikdash and that is because the exiles were on the level of baalei-tshuva. However, this didn’t occur and the 2nd Temple was destroyed.
The reason for that is there are many levels to tshuva and the ultimate level of tshuva wasn’t reached at that time. So the destruction that followed was meant to cause a deeper level of tshuva which will be realized at the time of the 3rdtachlis hashloimos, i.e. full and complete. Temple, that level of tshuva will be
Excerpted from a sicha, 5728