First of all, we must recognize that the spoken word is very powerful and that curses ARE real and they're very serious because they summon demons.
"Spells" in the Bible are always described negatively and are considered "detestable" to YHWH (see Deuteronomy 18:10-11); i.e., 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 and 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).
Believers do not need to worry about anyone casting any sort of pagan spell on them (Romans 8:11). 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 [Messiah] is greater than the one [Satan] who is in the world" (1 John 4:4).
However, on the other hand, curses don't necessarily have to be words uttered by a witch or someone with evil intent. They can also be in the form of words and/or actions, designed to belittle someone and make them feel badly about themselves; or having a habit of lying, cheating, committing adultery, gambling, generally being abusive toward people; or giving in to our desire to do things that can destroy our bodies (i.e., drug or alcohol abuse, etc.)
For instance, when a mother tells her children they are ugly and will never amount to anything, she has, in essence, cursed those children; and, chances are, they won't thrive mentally or emotionally, either during their childhood or when they become adults - because the more we’re told something negative about ourselves, the more we come to believe it!
More often than not, the mother treats her children that way BECAUSE she was treated that way herself - and, eventually, her children will grow up to do the same thing to their own children … because that’s what they were taught to believe, which remains “what they know.” In other words, they’ve been placed in a rut from which there’s seemingly no escape.
It’s a form of emotional and spiritual bondage that can be referred to as a “generational curse” caused by “generational sin” which keeps people from reaching their goals and becoming “all they can be”…
We are who we were made into during our formative years; and if we end up “being bad” in some way, it is a result of “generational curses.” Those can only be broken when we (1) recognize our faults and bad habits, and then (2) repent, turn from our ways, and (3) make up our mind to give ourselves wholly to YHWH, humbly asking HIM to change us into whom HE wants us to be.
Most people don't recognize generational curses (bad habits, carnality, things that are ungodly) and so they keep on doing what their carnal natures tell them to; and in the process they destroy their own lives, and the lives of their family, relatives and even their friends. It is a proven fact that children learn behaviors from their parents/guardians and pass those behaviors on to THEIR children!
We can find out “who we really are” and “who YHWH wants us to be” by reading His Word, from cover to cover, starting with Genesis and finishing with Revelation, as Scripture amply describes how to become a decent, responsible human being who is “set apart” for Him as He commands.
Here’s something to ponder:
Those who “put a curse” on one of YHWH's people (in any of the ways mentioned above), may actually end up having cursed themselves, instead – and they WILL give account of it to YHWH on Judgment Day!
Proverbs 26:2 says: “Like a fluttering sparrow or a darting swallow, an undeserved curse will come home to roost.”
The thing is, we can overcome ANY spell or curse with prayer - Halleluyah! Whenever something is "not right" in your life (no matter whether it's a general curse or from some outside source), simply pray for YHWH to take it away and totally give your life to Him. Satan has no power over those who belong to YHWH!