In Matthew 19:1-12, Jesus emphasizes God's original design for marriage—one man and one woman united for life. He rebukes the Pharisees' attempts to justify easy divorce, pointing instead to the hardness of human hearts as the reason for its allowance. While acknowledging biblical grounds for divorce, the sermon ultimately calls believers to honor marriage, flee sexual immorality, and rest in the grace of Christ, who redeems and restores His people, even when they fall.