My friend say Mormon rejoice in Adam’s transgression and my friend say only the ungodly people will rejoice in sinful things, so is he right?
You must not be concerned about attempts of those who do not understand the truth about religion to try to discredit the true kingdom of God established on the earth. Such barbs as those are only inspired by the adversary of all righteousness. If you were to satisfactorily answer your friend’s question, he would in all probability discard the answer and try to find some other point to use in attempting to discredit the Church. Actually, a satisfactory answer to your question would require a deeper understanding of the gospel than your friend would likely be willing to even listen to. But, for your own information, let’s see if we can provide such an explanation.
Adam and Eve, the first two inhabitants of planet earth, found themselves in the Garden of Eden, where they walked and talked with God. The greatest gift of God to mankind is the exercise of free agency. Man is given the right to make choices regarding right and wrong. In God’s economy, His children are never coerced into any given behavior mode. However, they are made responsible for the choices they make, and the Spirit of Christ is given to every man to inherently know the difference between good and evil. But although men are always free to make whatever choices they will, they are never free from the consequences of those choices. This makes all men responsible for their own behavior. So, in order to establish the free agency of man, God gave to Adam and Eve conflicting commandments. They were commanded to multiply and replenish the earth. They were also commanded not to partake of the fruit of the tree of knowledge of good and evil. Satan, not knowing the will of God, came tempting Adam and Eve to eat of the forbidden fruit. Adam resisted the temptation but Eve did not. As we read in 1 Tim 2:13-14—
For Adam was first formed, then Eve.
And Adam was not deceived, but the woman being deceived was in the transgression.
So when Eve partook of the forbidden fruit the consequence was that she would be expelled from the Garden of Eden, and cast out into the lone and dreary world.. With that separation, it would be impossible for them to fulfill the commandment to multiply and replenish the earth. So now Adam was faced with a dilemma–he could either obey the commandment not to partake of the fruit of the tree of knowledge of good and evil and thus not be able to fulfill the other commandment to multiply and replenish the earth, or, in order to fulfill that commandment he must break the other and partake of the forbidden fruit in order to be with Eve and fulfill the commandment of procreation. So Adam, knowingly violated what he considered to be the lesser commandment in order to comply with the greater commandment. The result of that decision made possible the generation of the entire human family, with the possibility for them to return to the presence of the Father if they would keep every commandment of God—
Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God. (Matt 4:4).