Today is an important day for many Jewish people in which they observe Tisha B'Av which is fast that memorializes the destruction of the First Temple by the Babylonians in 586 BCE and the destruction of the Second Temple by the Romans in 70 CE. The First Temple was built by King Solomon (1 Chronicles 28:1-6) while the Second Temple was built by Ezra and others under the permission of Babylonian kings. However, there will be a time when Jews no longer need to mourn the destruction of the Temple in Jerusalem because they look forward to the construction of a Third Temple in Jerusalem.
While Jews focus on the destruction of these two temples in Jerusalem, Biblical archeology and scholarship shows that there was never intended to be only one temple located in Jerusalem to be used in Jewish worship. The Bible supports the notion that having more than one temple was permissible under Jewish Law since in 2 Kings 12 we find tthat Jeroboam built new temples at Bethel (on Israel’s southern border) and at Dan (on the northern border).
Biblical archeology has discovered Jewish Temples at the following sites:
GilgalEbalShechemShilohKirjath-jearimGibeonMegiddoLachishDanBethelBeer-ShebaShechem/Mt. Gerizim (Samaritan)
The temples at Elephantine, Leontopolis, Tel Arad and others are not recorded in the Bible but are clearly identified as Jewish temples and were known by the Jewish leaders in Jerusalem. These archaeological sites along with no record of Jewish leaders objecting to them demolishes the claim that they would not have allowed to have a temple constructed outside of Jerusalem. It does not appear that these buildings were forbidden by Jewish law and practice. Unfortunately, these ancient temples were either destroyed or simply faded away with time. Only the Jewish Temple in Jerusalem remained and temple worship continued during and after Christ's mortal ministry on earth as demonstrated in the New Testament:
"...the New Testament apostles continued to worship in the Jerusalem temple after Christ's ascension (Acts 2:46, Acts 3:1-10, Acts 5:20-42). Even Paul worshipped there (Acts 21:26-30, Acts 22:17, Acts 24:6-18, Acts 25:8, Acts 26:21). Paul is explicitly said to have performed purification rituals (Acts 21:26, Acts 24:18), and prayed in the temple (Acts 22:17, cf. Acts 3:1); he claims that he has not offended "against the temple," implying he accepts its sanctity (Acts 25:8). Indeed, Paul also offered sacrifice (prosfora) in the temple (Acts 21:26, cf. Numbers 6:14-18), a very odd thing for him to do if the temple had been completely superceded after Christ's ascension. Finally, and most importantly, Paul had a vision of Christ ("The Just One" ton dikaion) in the temple (Acts 22:14-21), paralleling Old Testament temple theophanies, and strongly implying a special sanctity in the temple, where God still appears to men even after Christ's ascension."
Temples play a major role in LDS theology. Mormons believed those who escaped to the New World prior to the Babylonian invasion of Jerusalem as described in the Book of Mormon also brought the practice of Mosiac Temple worship with them. The Book of Mormon mentions the construction of two temples that occurred in different places and at different times with the first one being constructed shortly after those who fled before the Babylonian invasion arrived in the new world and the second one being built a few centuries later in city called Bountiful. These temples were constructed for Mosaic Temple worship just like they were done in temples in the old world.
Mormons believe that God restored the practice of Temple worship in modern times beginning with the construction of the Kirtland Temple to the construction of temples around the world. Temples will continue to play an important role in LDS theology and practice in the future. Mormons look forward to the construction of a Temple in Jerusalem.
In conclusion, this brief explanation is an attempt to explain why Mormons build temples around the world. Mormons believe that temples have historically been an essential part of God's church throughout time and space beginning with the time God instructed Moses to build the Tabernacle to the construction of the First Temple in Jerusalem to the construction of Temples in both the Old and New World to the multitude of LDS Temples that dot the globe to the construction of temples in the future.