By focusing on one aspect of our salvation, we, whether knowingly or unknowingly, minimize other aspects of our Christian Life. If justification is the entirety of our salvation experience, believers miss out on the joy and purpose of sanctification.
Dallas Willard summarizes it this way: The background assumption is that justification is the entirety of salvation. If you are justified — your sins forgiven — then you are saved and you will be “okay” after your death. I submit to you that this is what is offered, in still more specific forms, by current efforts (“evangelism”) to convert people to Christianity, and it is what people generally understand to be essential to the transaction.