God speaks—truth, and his people respond—spirit. While the term spirit, as I’ve mentioned, may imply the Holy Spirit here, the word can also refer to our inner spirits, and I think in the context of this passages, that is Jesus’s primary point. The woman had asked him about the proper outward physical place and method for worship, but Jesus emphasizes that in addition to the truth of God’s revelation being a necessary part of the worship God seeks, so also the inward response of our spirits is necessary for true worship.
Jesus’s conversation with the Samaritan woman in John 4 illustrates well the essence of worship with God as a relationship of communion with him. But where this passage helps us further is that it explains the nature of this all-satisfying communion with God. After Jesus uncovers the fact that the woman is seeking for satisfaction in sources that cannot satisfy, the conversation shifts to worship. This might seem like a completely different subject than what they were discussing, but actually, it continues the discussion by allowing Jesus to further explain the nature of the kind of communion with God that both satisfies the thirsty soul and brings honor to him:
The woman said to him, “Sir, I perceive that you are a prophet. 20 Our fathers worshiped on this mountain, but you say that in Jerusalem is the place where people ought to worship.” 21 Jesus said to her, “Woman, believe me, the hour is coming when neither on this mountain nor in Jerusalem will you worship the Father. 22 You worship what you do not know; we worship what we know, for salvation is from the Jews. 23 But the hour is coming, and is now here, when the true worshipers will worship the Father in spirit and truth, for the Father is seeking such people to worship him. 24 God is spirit, and those who worship him must worship in spirit and truth.” 25 The woman said to him, “I know that Messiah is coming (he who is called Christ). When he comes, he will tell us all things.” 26 Jesus said to her, “I who speak to you am he.”
There is much I could say about this idea of worship in spirit and truth, some of which we will notice in a later post, but for our purposes here, I want to emphasis the two-part structure of this worship—spirit and truth. These two elements are essentially connected grammatically; without one you cannot have the other. You cannot simply worship in spirit, and neither can you simply worship in truth. God is seeking those who will worship him in spirit and truth.