The following list of references is set out for easy comparison. Every aspect of the kingdom suggested previously, is tabulated, first, with the expression, "Kingdom of the heavens" as found in Matthew; secondly, with the term "Kingdom of God" as given in the other Synoptic Gospels. This comparison will enable the reader to see that the terms are largely interchangeable.
1. Kingdom in Power (Partially)
"Repent for the kingdom of the heavens in at hand" Matt 4:17
"The kingdom of God is at hand: repent" Mark 1:15
2. Kingdom in Patience (The mystic rule)
"It is given unto you to know the mysteries of the kingdom of the heavens" Matt 13:11
"Unto you it is given to the mystery of the kingdom of God" Mark 4:11
3. Kingdom in Present Possession (Spiritual)
"A rich man shall hardly enter into the kingdom of the heavens" Matt 19:23
"How hardly shall they that have riches enter into the kingdom of God" Luke 18:24
4. Kingdom in Profession (a sphere of responsibility)
"The kingdom of the heavens is like unto leaven" Matt 13:33
"Whereunto shall I liken the kingdom of God. It is like leaven" Luke 13:20,21
5. Kingdom in Prospect (The material in manifest power)
"With Abraham and Isaac and Jacob in the kingdom of the heavens" Matt 8:11
"With Abraham and Isaac and Jacob and all the prophets in the kingdom of God" Luke 13:28
Taken from the book The Kingdom in the Gospel of Matthew by Fred Cundick