Purity is likely closely related to the scripture term justification. But sanctification is something more, a becoming holy. It is something deeper. I’m not quite sure how to describe it, but I sense it is real.
” 29 And we know that all men must repent and believe on the name of Jesus Christ, and worship the Father in his name, and endure in faith on his name to the end, or they cannot be saved in the kingdom of God.
30 And we know that justification through the grace of our Lord and Savior Jesus Christ is just and true;
31 And we know also, that sanctification through the grace of our Lord and Savior Jesus Christ is just and true, to all those who love and serve God with all their mights, minds, and strength.” ( Doctrine and Covenants section 20).
Kip on Character 