This is absolutely critical. 1 Corinthians says, "Let two or three prophets speak, and let the others pass judgment." Prophecy is one place where God tells us to judge. If we share things that we are passing off as "God's Words" and it is false, then we are guilty of promoting false prophets. I never want anyone to turn away from God because I shared something that wasn't true.
It's on you to be responsible and check it out before sharing. What verses are they using? Read them and see if it sounds like what they are saying is true. Read online about what others are saying those verses mean. Get a good understanding of the historical setting of the passage. Pray and ask God to open your eyes. We will get it wrong sometimes, but at least put the effort into researching before you claim you speak for God.