Since you said you believe there is a heaven and
that you have behaved well enough to go there, you apparently believe there is a
God who offers heaven as a reward for those who in some way deserve it.
There is a very basic problem with saying there are
no moral absolutes and that everyone decides for themselves what is right and
wrong. This is one of those clear cut answers God gave us in the Bible.
God is very clear that there are absolutes, and that we should obey them; and if
we don't we will be judged! The 10 commandments are a prime example, in
fact the reason we have them engraved over our US supreme court building is that
the founding fathers recognized that even our government needed the moral
foundation that God provided through the 10 commandments. We as
individuals need it even more, our eternities are at stake.
If there is a God who is the final judge of our
actions, He must also set the standard for those actions. Otherwise there
could be no real justice. Everyone would just do what is right in their
own eyes. Hitler thought he was doing the right thing, and had no remorse
for his actions. Osama Bin Laden feels he deserves a reward for his
terrorism, which he believes honors God. Everyone can't be right.
God has to set the standard.
That's why we are so thankful that He left us His
Word, so we will know what He expects.