One of my children asked today (Easter) why God waited all through Saturday until Sunday before raising Jesus from the dead.
I think it relates to the Sabbath.
First, consider the very first Sabbath way back in Genesis 2. It says there that God set the Sabbath apart as holy because on that day He rested from all His work.
Why did God need to rest? Because He was tired? Of course not. The significance of God resting is that He was finished. He rested from all His work because it was complete. The Sabbath marked a recognition that there was nothing left to do.
What was one of the last statements Jesus made on the cross? “It is finished.”
I suspect the Sabbath after the crucifixion is meant to remind us that God’s second great work — the work of redemption — was finished with the death of Christ about 2000 years ago. Nothing needs to be added. We don’t have to mix our own good works in with what He did. He doesn’t need to be crucified again. That Saturday in the grave stands for the fact that everything had been accomplished.
A day later, the new creation began with the resurrection of Christ, the “second Adam”.