There is a plan of God designed for your salvation. It is not an afterthought or an attempt to correct a mistake. Rather, from all eternity, God determined that He would redeem for Himself a people, and that which He determined to do was, in fact, accomplished in the work of Jesus Christ, His atonement on the cross.
Your salvation has been accomplished by a Savior, One who did for you what the Father determined He should do. He is your Surety, your Mediator, your Substitute, your Redeemer. He atoned for your sins on the cross. "
— R. C. Sproul, The Truth of the Cross, (Orlando, FL: Reformation Trust Pub., 2007), 152-153