I just had to share this quote with you, do pop by the blog I found it on to read the rest of the article. The writer is speaking about a verse in 1 John which says essentially that the Holy Spirit is directly involved in giving us assurance of salvation. There is some similar material in my book Raised With Christ, but to be honest, I think this guy says it more clearly than I did here, and much as I know many of my loyal readers would disagree, I am not ashamed to nail my colors to the mast on this point:
Notice that John isn’t saying if we are Christians, we know we have the Spirit; he is saying if we have the Spirit, we know that we are Christians.This reminds me of Acts 19:2, where Paul asks some men if they received the Spirit when they believed. Paul is assuming they know whether Almighty God came upon them or not; an assumption we no longer make. Lastly, there is the passage in Acts 8 where Simon goes to Samaria and leads many to Christ, but the apostles “…came down and prayed for them that they might receive the Holy Spirit. For He had not yet fallen upon any of them; they had simply been baptized in the name of the Lord Jesus.” Forget for a moment that this passage is theologically incredible. For our purposes, just note that they knew the Holy Spirit hadn’t fallen on these believers. They could tell that the Spirit hadn’t come upon them. Maybe Christians shouldn’t assume the Spirit is present and acting when there is no evidence. According to the Bible we should be able to tell, at least some of the time.
via The Holy Spirit as Evidence of our Salvation « Scholarship in the Glory. (emphasis added)