Also, God's attitude toward a person is changed when the person becomes a Christian. Mormonism denies the immutability of God. To reckon to someone the blessing, curse, debt, etc. of another. Therefore, our sins are forgiven. Understanding imputation is very important.
Imputation is the means of our salvation.
Our sins were put upon, imputed, to Jesus on the cross. When He died on the cross, our sins, in a sense, died with Him. The righteousness that was His through His perfect obedience to the Father in His complete obedience to the Law is imputed, given, to us. In short, our sins were given to Jesus. His righteousness was given to us.