The Cross not only atones but also models a way of life.  McKnight, Scott. Kingdom Conspiracy, 173.

The cross reminds us that Jesus' death not only atones for our sin and makes it possible for us to be reconciled and restored to God through Jesus Christ,  it also reminds us that taking up our own cross is the requirement of the Christian life (Mat 10:38; 16:24).  Jesus said that unless “If anyone would come after me, let him deny himself and take up his cross and follow me.  To deny oneself means to die to our own desires to be our own king ruling our own kingdom agenda and submit to King Jesus and his kingdom agenda!  In short, it means to die to our own self-will and embrace God's will at all cost.