Question: "Can a Christian be cursed? Will God allow a curse on a believer?"
Answer: The Bible tells us that “like a fluttering sparrow or a darting swallow, an undeserved curse does not come to rest” (Proverbs 26:2b). This means that foolish curses have no effect. God does not allow His children to be cursed. God is sovereign. No one has the power to curse one whom God has decided to bless. God is the only One able to pronounce judgment.
“Spells” in the Bible are always described negatively. Deuteronomy 18:10-11 numbers those who cast spells with those who commit other acts “detestable to the LORD” such as child sacrifice, witchcraft, sorcery, divination, or necromancy (consulting with the dead). Micah 5:12 says that God will destroy witchcraft and those who cast spells. Revelation 18 describes spells as part of the deception that will be used by the antichrist and his “great city of Babylon” (v. 21-24). Though the end-times deception will be so great that even the elect would be deceived if God did not protect us (Matthew 24:24), God will utterly destroy Satan, the antichrist, and all who follow them (Revelation chapters 19-20).
The Christian has been born again as a new person in Jesus Christ (2 Corinthians 5:17), and we are in the constant presence of the Holy Spirit who lives within us and under whose protection we exist (Romans 8:11). We do not need to worry about anyone casting any sort of pagan spell on us. Voodoo, witchcraft, hexes, and curses have no power over us because they come from Satan, and we know that “the one who is in you [Christ] is greater than the one [Satan] who is in the world” (1 John 4:4). God has overcome him, and we have been freed to worship God without fear (John 8:36). “The Lord is my light and my salvation—whom shall I fear? The Lord is the stronghold of my life—of whom shall I be afraid? ” (Psalm 27:1).