I've really held back on asking this for a quite some time now, hoping someone else will bring it up. But I suppose by now, I have no choice.
For a curse to be effective, does the person need to intentionally practice it? Or could someone wishing me ill intensely bring it to pass?
I've recently read a thread about someone being cursed by someone else's negative remarks spoken over his/ her life, which hinted to me that curses could occur unintentionally.
Every curse that has power comes from the demonic realm. There is a story in the bible about the disciples not being able to cast out a demon, when they asked Jesus why he said "it was due to their unbelief, and appended but this kind only comes out by prayer and fasting".
Demons are always looking for ways to harm, and curse us. As the bible says "the devil goes around like a roaring lion looking for whom he may devour".
But the reality is in Christ, we are seated in heavenly places, with authority over Satan, due to the work of the cross. The bible further tells us that "Christ became a curse for us, that we may inherit the blessing of Abraham". This means that Christ took the curses, and the curse of Satan, and "made a display of them openly".
We can now walk free of the curses of Satan. (Generally) The only thing that can allow Satan to stay, or curse us, is our own unbelief, as the disciples were unable to cast out the demon due to unbelief, some times we as Christain's allow curses to stay due to not having faith to remove it.
How do you get faith, Jesus said "if you have faith the size of a tiny seed you will say to this mountain be picked up by the roots and it will move". You don't need to do anything to get bigger faith, you have the seed of faith Christ.
But if like the disciples you still struggle with believing the curse is broken, what did Jesus tell them they needed to do? Pray, spend more time in prayer, even fast if needed.