I would like to share two quotes from Leon Morris today (HT Gospel Driven Life). These express the substitutionary view of the atonement well:

“To put it bluntly and plainly, if Christ is not my Substitute, I still occupy the place of a condemned sinner. If my sins and my guilt are not transferred to Him, if He did not take them upon Himself, then surely they remain with me. If He did not deal with my sins, I must face their consequences. If my penalty was not borne by Him, it still hangs over me. There is no other possibility.”

— Leon Morris, The Cross on the NT

“It is an outstanding merit of the substitutionary view, then, that it does not gloss over the past. It recognizes it for the serious and significant thing that it is. But it affirms that Christ has taken care of our past as He has taken care of every aspect of our need. He has paid the penalty. He has wiped out the sin.”

— Leon Morris, The Cross on the NT

Continues with “The Atonement – An Attack on Penal Substitution.”