|Mark 1:14 Now after that John was put in prison, Jesus came into Galilee, preaching the gospel of the kingdom of God,||Matt 4:12 Now when Jesus had heard that John was cast into prison, he departed into Galilee;||Luke 4:14 And Jesus returned in the power of the Spirit into Galilee: and there went out a fame of him through all the region round about. 15 And he taught in their synagogues, being glorified of all.|
Matt 4:13 And leaving Nazareth, he came and dwelt in Capernaum, which is upon the sea coast, in the borders of Zabulon and Nephthalim: 14 That it might be fulfilled which was spoken by Esaias the prophet , saying, 15 The land of Zabulon, and the land of Nephthalim, by the way of the sea, beyond Jordan, Galilee of the Gentiles; 16 The people which sat in darkness saw great light; and to them which sat in the region and shadow of death light is sprung up.
|Mark 1:15 And saying, The time is fulfilled, and the kingdom of God  is at hand: repent ye, and believe the gospel.||Matt 4:17 From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand.|
Isaiah 9:1 Nevertheless the dimness shall not be such as was in her vexation, when at the first he lightly afflicted the land of Zebulun and the land of Naphtali, and afterward did more grievously afflict her by the way of the sea, beyond Jordan, in Galilee of the nations. 2 The people that walked in darkness have seen a great light: they that dwell in the land of the shadow of death, upon them hath the light shined. Isaiah is speaking of Israel.
The phrase "kingdom of God" is used frequently by Jesus in Mark (13 times) and Luke (24 times) but only twice in John and five times in Matthew (who prefers "kingdom of heaven"). Appearances of "God" and "heaven" in parallel will not be marked as contradictions after this point.