I am learning to listen to warnings like that faster and more immediately. Yes as a human being, I can err but I believe we all need to be listening when God is warning us of something. This may sound odd, but I had the thought too this person had some involvement with occultism. On the surface they are in a false church, and I met them in a community context.
I found out via public information on the internet someone closely related to this person is basically a Satanist. And I am not talking teen "Goth" or "Wicca" dabbler or a few bouts of yoga or rekki but a well into adulthood HARD CORE Satanist. Think "OTO" temple one with Silver in the name and interest in esoteric "magic", some with names I am sure no one ever heard of but I have from my younger days. And it went even further then that. Some may say it is unfair to judge a relative on what another relative is doing. And on that they would be right. Many good Christians come out of wicked families, but this specific person on a public Facebook page, drew pictures of themselves surrounded by demons. They praised their Satanic family member to me when I first met them.
I believe God is helping to protect me from future betrayals . I hope people do not think I have lost it or gone "paranoid". I didn't act on a lot of warnings that came early when dealing with two major betrayals. I paid for not listening sooner. With one person, who was a deceiver, I had dreams about them for a long time. I "knew inside" but was afraid to act. The dreams told me over and over they were not what they appeared to be. Here is a place where a Christian will want to go with your gut. If all your "instincts" tell you something is wrong, the message is coming from somewhere. Listen to the small voice of the Holy Spirit! I hope with time I have grown stronger. Some will tell you everything you want to hear. Some will even pretend to be Christians. Some will pretend to even be a fellow new world order aware Christians.
One person still lauded her involvement in an Eastern Star organization for the young, and I gave too many breaks thinking they were an "ordinary" unsaved person that I could reach with the gospel who I thought sadly had just been lured into the Rainbow girls when young. That was not to be. Even there I had warnings about her true spiritual position, and waited too long. Sometimes we have to face the disappointment or losing a would be "friend" who really isn't.
I am not saying I am better then any of these people, some I believe I dealt with are seared but others, I pray will be born again and come to Jesus Christ. One thing I am thinking about is discernment is nothing to play around with and as we walk with the Lord, we need to be paying attention. As the days grow darker, this is more important then ever. I know I still have a lot to learn but I have had my times of being unseasoned in some ways. I have to remind myself to listen to discernment and in testing the spirits. Sometimes we will make mistakes, but God's protection is there for the asking.