Genesis 2:24 Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh.

This is what Jesus referred to in Mt.19:5 on the question of divorce,
He answered and said to them, "Have you not read that He who made them at the beginning 'made them male and female,' which was permitted by Moses Matthew 19:8-9
He said to them, "Moses, because of the hardness of your hearts, permitted you to divorce your wives, but from the beginning it was not so.

Mormons use the infidelity of Jacob in Gen. 29-30 and Abraham to justify polygamy but they go even further than this stating that in their Mormon gospel it gives one exaltation, to become a god on another planet and have many wives to populate it (as Elohim did in spirit in his preexistence, and on earth).

The bible teaches of those in both leadership and serving in the church:  bishops in 1 Timothy 3:2 and deacons 1 Tim.3:12 to be a husband of one wife.

In Mt.22:30 The Sadducees who did not believe in a resurrection or an after life asked Jesus about a man dying and his brother marries his wife, and then he dies. Seven times this happens ( which would make the wife suspect of something fishy). They ask in the resurrection whose wife will she be. Jesus answers that they are mistaken, not knowing the scripture or the power of God in the resurrection. They neither marry nor are given in marriage but are like the angels of God in heaven. In other words there is no expansion of a family (no procreation) and there is no family unity, they are single. There are no offspring in heaven, the angels do not marry and have children so according to the Bible the Mormon teaching of the family in the afterlife is very wrong. The Mormons deny polygamy on earth but allow it in heaven according to their own teaching.

Since this  is a moral command from creation, the question one needs to understand - would God allow in heaven what he forbids on earth? Heaven is supposed to be pure and without disobedience to God. By the very fact they do not allow it on earth should make it understood that it is a false teaching of theirs to say that it is allowed it in heaven. The family forever teaching of Mormonism is not a Biblical teaching.