Some experiences come from God, some from the devil. Here is a quote of a demon, or demons giving blissful experiences.
Sit like that meditating all day and all night without talking? A month? Two months? A year? I did it for over three years! For over three years I sat in that chair and went up into heaven and down into hell for 23 hours a day. What do you think would happen to someone that did such a thing? You go nuts. I had more voices in my head than you have on your local radio station. These voices would come with amazing powers. They could accurately predict the future. At times, they would tell me who was going to come into the dome several minutes before he arrived! They could give bliss. Seemingly they could do whatever your heart wanted. I remember one day walking from my dome to my bathhouse, when a voice came to me and said, “Step on that crack and I will give you bliss.” I immediately stepped on the crack. A blissful feeling came over me so strong that I collapsed onto the ground. I don’t know how long I lay there, startled, shining from the experience. What would you do with such a voice? I followed whatever it said to do. For a while, all seemed to go well. But then it started to scream at me and command me to do insane things like, “Bang your head on that wall. Again, harder.” Then the voices started to lie to me. They drove me completely nuts.
Locks, Gil. Coming Back to Earth: The Central Park Guru Becomes an Old City Jew (pp. 147-148). Mystical Paths eBooks. Kindle Edition.
But it’s not that every single experience outside of Christianity is demonic. As a matter of fact, probably lots of experiences INSIDE are demonic.
The best measure so far is humility and pride. If it leads to pride, self-deification, if the fruits are evil, it’s evil. If it leads to humility, if it’s good the fruits will allways be compassion, joy, and life.
Never fall for the “all religions and experiences are equal and from the same source” lie. It only brings death and spiritual desolation.
As one saint said - if you reject an experience because of the desire for Truth and for God, He will find in his goodness another way to talk to you.