Paying the Consequences for Sin

I have members of the church allude and outright declare that justice must be exercised on those who sin regardless of whether they have repented or not. I have always disagreed with these people. I leave mercy in God's hands. He can, if he chooses to waive the consequences of sin to some degree.

For example, when the angel came to Alma and the sons of Mosiah, they were stopped in the tracks in their quest to destroy the church of God. They could either repent of be destroyed. When the repented, God show great mercy on them. Look at the following verse:

Alma 26:20 Oh, my soul, almost as it were, fleeth at the thought. Behold, he did not exercise his justice upon us, but in his great mercy hath brought us over that everlasting gulf of death and misery, even to the salvation of our souls.

Now Alma and his brethren did receive persecution from the unbelievers. That was a consequence of changing from a sinful state to a righteous state. That wasn't taken away. I can see that the agency of others to persecute another isn't taken away.