Contradiction with Matthew 10:34
Malachi 3:1 speaks of preparing the way for a peaceful coming of the Lord, while Matthew 10:34 mentions Jesus bringing division instead of peace.
Matthew 10:34: Think not that I am come to send peace on earth: I came not to send peace, but a sword.
Contradiction with John 6:15
Malachi 3:1 anticipates a divine messenger coming with a clear purpose, whereas John 6:15 shows people misunderstanding and attempting to forcefully make Jesus king.
John 6:15: When Jesus therefore perceived that they would come and take him by force, to make him a king, he departed again into a mountain himself alone.
Contradiction with Luke 17:20-21
Malachi 3:1 predicts an observable preparation, while Luke 17:20-21 teaches the kingdom of God comes without observable signs.
Luke 17:20-21: And when he was demanded of the Pharisees, when the kingdom of God should come, he answered them and said, The kingdom of God cometh not with observation: [with...: or, with outward shew]
Contradiction with Revelation 1:7
Malachi 3:1 suggests a gradual, prepared coming, whereas Revelation 1:7 describes an unexpected, immediate revelation seen by all.
Revelation 1:7: Behold, he cometh with clouds; and every eye shall see him, and they [also] which pierced him: and all kindreds of the earth shall wail because of him. Even so, Amen.