Do u believe that there is only one GOD?

Its not actually about "heaven", it's about eternal life or eternal death. Most people, due to biblical illiteracy, have misunderstood what Scripture says about that. Heaven is not where people "go" when they die to spend eternity. Thsoe that are found righteous will be here on the restored earth under the ultimate rule of the Son of G-d. There will still be many kingdoms and countries and peoples, but all united under Him.