How did Jesus' dying open the gates of heaven?

Jesus' death is believed to have opened the gates of heaven by providing a means of atonement for humanity's sins. According to Christian theology, His sacrifice fulfilled the requirements of justice and mercy, allowing for reconciliation between God and humanity. This act of love and obedience not only redeemed sinners but also offered the promise of eternal life to all who believe in Him. Thus, through His death and subsequent resurrection, Jesus is seen as paving the way for believers to enter heaven.