Kingdom Of God & Kingdom of Heaven

---

The kingdom of God is the same with the kingdom of heaven. 

Some Christians believe that the kingdom of heaven is God’s ruling in heaven, and the kingdom of God is His ruling here on earth.

As declared in the third commandment, the name of God is considered too sacred to be carelessly uttered or be vainly used:

Exodus 20:7
You shall not take the name of the LORD your God in vain, for the LORD will not hold him guiltless who takes His name in vain.

Thus, when Jesus used the expression "kingdom of heaven," He was saying the exact same thing as "kingdom of God." "Heaven" is an equivocal synonym for "God."

There is only One Kingdom, and the One King reigning in His Kingdom is God Himself.

Matthew 6:10 
Your kingdom come.
Your will be done
On earth as it is in heaven.

Interestingly, the Chinese also used "Heaven" as a honorable reference to "God."