 Some believers suffer with what I call religious OCD. This is to say that they suffer with intrusive or obsessive thoughts about biblically-themed fears. For example, they may be daily and constantly tormented by the thought that they committed the blasphemy of the Holy Spirit, lost their salvation, or lost the call of God. They may even fret about the future. Am I going to miss the rapture? Will a demon enter me, even though I'm filled with the Holy Spirit? Will God reject me on Judgment Day? Well, we should maintain a holy fear of God's judgment and live clean. It's not God's will for believers to live in torment, uncertainty, and a constant second guessing of their identity. So then, the tormented believer asks questions obsessively about these topics. But even when they receive what should be peace-giving truth on these matters, their minds find something else to worry about, how to be free. Here's at least one key. Learn to catch your worst-case scenario thinking, then allow the Holy Spirit to intercept that lie with the biblical truth that contradicts it. For more on this, see the video suggestion in the comments.