The obvious choice for this month—given Easter is observed in April—is the One who created and redeemed the world: Jesus Christ. Others who have come after the Son of God have left legacies that have changed the world in their lifetime, or maybe even for centuries, but no one has or will change the world for the remainder of its existence, that is other than Jesus. Becoming human, dwelling with us, dying for us, rising to new life, and ascending to his heavenly realm to prepare a place for us, Jesus Christ, our Messiah has accomplished what no other human could do: bring forgiveness, reconciliation, and restoration to those who God has called to be his children:
For he himself is our peace, who has made us both one and has broken down in his flesh the dividing wall of hostility by abolishing the law of commandments expressed in ordinances, that he might create in himself one new man in place of the two, so making peace, and might reconcile us both to God in one body through the cross, thereby killing the hostility. Ephesians 2:14-16 ESV
In doing so, he has taken away the sting of death that has haunted every human being since the Fall of Adam:
The sting of death is sin, and the power of sin is the law. But thanks be to God, who gives us the victory through our Lord Jesus Christ. 1 Corinthians 15:56 ESV
So when we consider world changers like Martin Luther King, Jr., Abraman Lincoln, and Saint Patrick, the best they can offer is an imperfect representation of the One who perfectly brought healing and new life to every nation for all of history. And the Cross beautifully portrays his sacrificial love that brings it all together. Jesus is the ultimate reality of what it means to be a world changer.