On Passover a lamb's blood was placed on the lentel and post so the plague upon the first born son would passover the home.

On Easter, it is a celebration of Christ's blood being placed within our lives so God will passover our sins and the visual celbration of Christ's power over death.

It was not "just coincidental" that Christ, "the Lamb of God" was crucified on the eve-of the Passover.