An evangelist that came to my church taught on this. He said, when in doubt, to test the spirit. To ask the spirit, three times, "did Jesus Christ come in the flesh?"
He cited I John 4:1-6.
Also see in the New Testament in I Cor. 12:3. "Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Spirit."
If something you hear does not edify the Lord God, pray about it. Ask the Lord to guide you through and provide what you need to discern. If you feel a negativity, you can rebuke that, but only in the name of Jesus. We can do nothing except by the power of His precious blood.
Here is a website on discerning of spirits:
Discerning of Spirits - Gift of the Holy Spirit Testing The Spirits
Hope this helps.