I just finished reading The Truth of the Cross by RC Sproul. This is probably one of the best books on the atonement that I've ever read. Sproul's book is dense, but easy to read and understand. He spells out the doctrines of grace and preaches the gospel very clearly throughout the book.
He begins the book with the fact that the atonement is necessary now, because it is such a debated issue. Sproul explains that God is just and would be right in punishing us for all of eternity. We are criminals, debtors, and enemies of God. But God having a plan sent his son in the person Jesus Christ to die upon the cross to be a ransom for those who would believe. The ransom Christ paid purchased his Bride and released us from the bondage of sin.
Sproul covers atonement, redemption, substitution, expiation, propitiation, and salvation. Helping the reader understand each of these theological words in a way they'd be able to explain it on their own.
One of the areas in this book that really put things into perspective for me was when Sproul writes that Christ was forsaken on the cross. The idea that Christ while on earth had intimate communion with the Father, then at the time of his death he was forsaken by the Father. This was in order that anyone could be redeemed and saved....
“The hard reality is this: if Jesus was not forsaken on the cross, we are still in our sins. We have no redemption, no salvation. The whole point of the cross was for Jesus to bear our sins and bear the sanctions of the covenant. In order to do that, He had to be forsaken. Jesus submitted Himself to His Father’s will and endured the curse, that we, His people, might experience the ultimate blessedness.”
This book will center your attention to the cross, Christ, and the atonement. It's available from Reformation Trust.