Here are some texts from Mark 13 that muddy the clear waters of tradition when it comes to the meaning of “heaven.”
Mark 13:25: the stars will fall from the sky [heaven], and the heavenly bodies will be shaken.
Mark 13:27: And he will send his angels and gather his elect from the four winds, from the ends of the earth to the ends of the heavens.
Here’s a very interesting statement:

Mark 13:31 Heaven and earth will pass away, but my words will never pass away.
Mark 13:32 No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father.
First, heaven here refers to what is up, the sky.
Second, heaven is in contrast to earth.
Third, skipping to 13:32, heaven is where the angels are.
Fourth, this statement, taken literally, means “heaven” is not eternal. It is no more eternal than earth. The word of Jesus is eternal but heaven is not.
This could be the discovery of a gold nugget. Does this text teach that heaven is not eternal, that it is a “temporary” abiding place of God and the angels? Or, is this simply a trope, a figure of speech? But quite odd for someone like Jesus even to say that heaven is not eternal if it really is. I suggest, the former — heaven is the temporary abiding place of God and the angels, a place to which some go, but it is not the eternal resting place.