Why did Jesus explain His sufferings to His disciples?

In Matthew 16:21, Jesus begins to reveal to His disciples the nature and necessity of His impending sufferings. This preemptive teaching serves multiple purposes: it prepares the disciples for the shock of His crucifixion, establishes the significance of His death as a fulfillment of God's redemptive plan, and helps them understand that their own following of Him involves embracing a path of suffering. The explanation underscores the concept that true discipleship involves accepting the hardships associated with following a Savior who Himself endured great suffering for their sake.