Christ's teaching to the Samaritan woman at the well: God is a Spirit: and they that worship him must worship him in spirit and in truth (John 4:24). The phrase corrects two opposite errors. In spirit rules out merely external, ritualistic, geographically-bound worship — the specific issue the woman raised about Gerizim vs. Jerusalem. In truth rules out merely emotional, subjective, doctrinally-loose worship — the modern temptation that opposite-corrects the first error and lands in a different ditch. True worship is heart-engaged AND doctrinally grounded: the Spirit-quickened soul responding to the truth of who God actually is, on the basis of what He has actually said. Either pole alone fails. Both together are what the Father seeks.