Are all prophecies from God?

Not all prophecies are from the Lord – Holy Spirit! Many are by demonic spirits sent by Satan to trick and deceive.
“And it came to pass, as we went to prayer, a certain damsel possessed with a spirit of divination met us, which brought her masters much gain by **soothsaying:” Acts 16:16

**Soothsaying: Strong’s # G3132 – “μαντεύομαι manteúomai, mant-yoo’-om-ahee; from a derivative of G3105 (meaning a prophet, as supposed to rave through inspiration); to divine, i.e. utter spells (under pretense of foretelling:—by soothsaying. – to act as a seer, deliver an oracle, prophesy, divine.”

This is one of the reasons we are called to try the spirits to see if they are from God.
“Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world.” 1 John 4:1

In my opinion God has given all the prophecies we need to know in His word. Anything added to that is very suspect to me.
To me, getting prophecies about what is going to happen to us in the future is akin to getting your fortune told by a psychic or tarot card reader, which is of course forbidden in the Bible.
I’ve experienced these kinds of “prophecies” first hand, and people honestly thought they were from the Holy Spirit, but I can tell you that they weren’t. Now I understand where they were truly coming from.

Please, please be careful when someone “prophesies” over you or especially your children, because they could well be possessed with a demonic spirit of divination. The consequences of this could be very hard to get rid of.
If this is you, then I urge you to repent; understand that it’s wrong to receive these kinds of prophecies and stop receiving them.