Praise be to Allah, and peace and blessings be upon the Messenger of Allah. To proceed:
The fact that some incantations or charms used by non-Muslims appear to have an effect does not prove that those religions or their beliefs are true.
Healing or the occurrence of something extraordinary does not necessarily mean that the person involved is following the truth, because such things may happen for several reasons.
A person may call upon his Lord in a state of extreme distress and with great sincerity, and Allah may answer him even if he is not a Muslim.
Allah says:
“Is He not the One Who responds to the distressed when they cry to Him, relieving their affliction?”
Allah is the Lord of all worlds. He answers the distressed and shows mercy to the oppressed. He may grant a non-Muslim something in this worldly life, not because He approves of disbelief, but as a manifestation of His justice and lordship.
Therefore, healing or relief from suffering may occur because of genuine desperation, strong psychological focus, supplication, or a known psychological or physical effect.
This does not mean that Buddhist beliefs or any other beliefs are true.
Some charms and rituals may involve appeasing the jinn, asking them for assistance, or drawing closer to them through certain rituals.
Some jinn may then serve such people in exchange for acts of shirk or false rituals.
Allah says:
“And some men from humankind used to seek refuge with some men from the jinn, so they only increased them in burden.”
Therefore, a real effect may sometimes appear, but it is a forbidden effect based on a corrupt relationship with the jinn, similar to magic and fortune-telling.
Some incantations and rituals may affect a person psychologically through suggestion, relaxation, concentration, and the strength of belief.
Likewise, there are beneficial medicines developed by non-Muslims, even though their creators do not follow the true religion.
Therefore, achieving a result does not prove that a belief is true.
Islam is not proven true merely because it contains ruqyah, nor are other religions proven false merely because they contain some practices that provide worldly benefits.
Rather, the truth of Islam is established through the Oneness of Allah, the truthfulness of the Qur’an, the prophethood of Muhammad ﷺ, the consistency of its beliefs, and rational and revealed evidence.
The occurrence of certain benefits or extraordinary phenomena among non-Muslims does not prove that they are upon the truth.
There may be a skilled doctor who is a non-Muslim, a magician who influences people while being a non-Muslim, a monk who experiences extraordinary phenomena while being misguided, or a righteous Muslim through whom no extraordinary events occur at all.
Truth is not measured by extraordinary phenomena, but by authentic revelation and the worship of Allah alone.
And Allah knows best.