I don't know why I am writing this. But I felt this is interesting. (This is not a ground-breaking observation and may be baseless)

So the question is how far is heaven from earth.

Let us make some analysis:

It is known that a day in heaven is equal to 1 year on earth.

This means that 365 days on heaven is equivalent to 365 years on earth.

Now Pluto is at a distance of about 5,913,520,000 KM and it takes 248.54 years to revolve round the sun.

This means that for a body that takes 365 years to revolve round the sun (a vague assumption), it should be roughly at a distance of 9,000,000,000 KM from the sun. And considering the distance of earth from sun, we can safely neglect it and say that this is the distance of heaven from earth.

And if my calculations are not wrong, it will take you about 8 hours to reach there if you travel at the speed of light.