There must be a sacrifice to make both Abraham and Isaac right with God. Because of sin none of us are right with God. Sin is serious business. If anything matters, sin matters. It matters deeply and profoundly.
Sin is so serious that it demands a sacrifice.
Many people today do not take sin seriously. Many people today do not realize the terribleness of sin. Many people today do not realize that sin demands punishment and that only sacrifice removes that punishment and makes one right with God. Yet, that is Scripture's clear teaching. When Abraham looked up, what does he see but a ram caught by its horns in a thicket.