In the JST, Joseph would make changes to KJV texts that speak of God hardening the hearts of people such as Pharaoh. However, in Joseph Smith’s translations and revelations, God did affect the “heart” of people, often by softening it. In the Book of Mormon, we have the following examples:
And
it came to pass that I, Nephi, being exceedingly young, nevertheless being
large in stature, and also having great desires to know of the mysteries of
God, wherefore, I did cry unto the Lord; and behold he did visit me, and did
soften my heart that I did believe all the words which had been spoken by my
father; wherefore, I did not rebel against him like unto my brothers. (1 Nephi
2:6)
And
it came to pass that the Lord did soften the heart of Ishmael, and also his
household, insomuch that they took their journey with us down into the
wilderness to the tent of our father. (1 Nephi 7:5)
And
there was nothing save it were the power of God, which threatened them with
destruction, could soften their hearts; wherefore, when they saw that they were
about to be swallowed up in the depths of the sea they repented of the thing
which they had done, insomuch that they loosed me. (1 Nephi 18:20)
Wherefore,
my beloved brethren, thus saith our God: I will afflict thy seed by the hand of
the Gentiles; nevertheless, I will soften the hearts of the Gentiles, that they
shall be like unto a father to them; wherefore, the Gentiles shall be blessed
and numbered among the house of Israel. (2 Nephi 10:18)
Therefore
they hushed their fears, and began to cry unto the Lord that he would soften
the hearts of the Lamanites, that they would spare them, and their wives, and
their children. (Mosiah 23:28)
And
it came to pass the the Lord did soften the hearts of the Lamanites. And Alma
and his brethren went forth and delivered themselves up into their hands; and
the Lamanites took possession of the land of Helam. (Mosiah 23:29)
And
behold, I thank my great God that he has given us a portion of his Spirit to
soften our hearts, that we have opened a correspondence with these brethren,
the Nephites. (Alma 24:8)
In the Doctrine and Covenants, we
have the following examples:
And
inasmuch as you are diligent and humble, and exercise the prayer of faith,
behold, I will soften the hearts of those to whom you are in debt, until I
shall send means unto you for your deliverance. Therefore write speedily to New
York and write according to that which shall be dictated by my Spirit; and I
will soften the hearts of those to whom you are in debt, that it shall be taken
away out of their minds to bring affliction upon you. (D&C 104:80-81)
And
I will soften the hearts of the people, as I did the heart of Pharaoh, from
time to time, until my servant Joseph Smith, Jun., and mine elders, whom I have
appointed, shall have time to gather up the strength of my house, (D&C
105:27)
And
again, I will visit and soften their hearts, many of them for your good, that
ye may find grace in their eyes, that they may come to the light of truth, and
the Gentiles to the exaltation or lifting up of Zion. (D&C 124:9)