The second statement of belief Joseph Smith wrote to John Wentworth is as follows,
We believe that men will be punished for their own sins, and not for Adam’s transgression.
This deals with the idea of original sin, something that Latter-day Saints do not believe in. Mankind is born innocent, and later learns how to sin and develop corrupt behavior. Through the atonement of Jesus Christ, children who die before they are of age are saved. They have no sin, and therefore they are alive in Christ.
The Savior taught,
But Jesus said, Suffer little children, and forbid them not, to come unto me: for of such is the kingdom of heaven. (Matthew 19:24)
Every man and woman will be held accountable for their own actions. The choice that Adam and Eve made is not upon our heads. (For more info on the Fall of Adam and Eve, check out my blog post here.)
We are agents unto ourselves. Our free agency is the greatest gift from God that we have right now. The Book of Mormon teaches,
Therefore, cheer up your hearts, and remember that ye are free to act for yourselves—to choose the way of everlasting death or the way of eternal life. (2 Nephi 10:23)
Whether we choose good or evil, it is our choice and only our choice. No one can or will make it for us.