If God really did become fully human when He became incarnate as Jesus – which is the theology I was taught as a kid – that means He became limited by that humanity. That’s why He wasn’t able to prevent his abortion. And having been killed on Friday night, He was as dead as anybody else.
So imagine His surprise when He returns to life on the third day.
Of course Jesus wasn’t completely limited by His human incarnation. He did miracles, walked on water, etc. So giving Himself the ability to stand and talk is within the kinds of things He did in the gospels.