Easter is a Christian feast and holiday celebrating the resurrection of Jesus Christ. According to the New Testament, Jesus Christ was crucified at Calvary. To understand how the resurrection of Jesus Christ correlates to the spring equinox, you have to understand that Jesus Christ is an allegory of the sun.
This will offend a lot of people but Jesus Christ is a sun god. He is the anthropomorphic representation of the sun in bronze-age mythology.
Regardless of Christian history, people celebrate the spring equinox throughout the world in every culture.
The ancient Saxons in Northern Europe worshiped the Goddess Oestre at the time of the Spring Equinox. The Goddess Easter represents the sunrise, spring-time, and fertility, the renewal of life.
The story of the Roman god, Mithras, is similar to the tale of Jesus Christ and his resurrection. Born at the winter solstice and resurrected in the spring, Mithras helped his followers ascend to the realm of life after death.
The indigenous Mayan people in Central American have celebrated a spring equinox festival for ten centuries.
Many myths revolve around the astronomical event but there is nothing magical about it other than what we make of it. The term equinox is derived from the Latin words, aequus (equal) and nox (night).