In his first Epistle St. John gives three indicators that we have the Spirit and so abide in Him and He in us. The first is that we keep the commandments of Jesus. The second is that we confess that Jesus Christ has come in the flesh. The third is that we “love one another.”
Notice there is nothing there about the charismatic gifts. Notice there is nothing there about the subjective inward look for the Spirit’s footprints that so many Pietists love. Really, the inward look, to one who is sensitive to God’s absolute standard of perfection is a recipe for despair. “I know that in me no good thing dwells.”
Note also how the Westminster Confession corresponds so well with St. John when it talks about the necessity of deed, word, and thought; or if you prefer, action, belief, attitude.
Keep in mind here that love (in the necessity to “Love one another”) can only be identified and defined by God’s law. The appeal here isn’t to a warm fuzzy feeling. The appeal here is to love as a verb… love shows action and the action it shows is treating our neighbors consistent with God’s revelation of Himself in his law.