In John 4:24 Jesus lays down two basic elements for acceptable worship. There, our Lord said, "God is Spirit, and those who worship Him must worship in spirit and truth."
In the context there is a discussion concerning the place of worship. The Samaritan woman brought up the controversy between the Jews and Samaritans about where to worship. The Jews pointed to Jerusalem while the Samaritans pointed to Mt. Gerizim (v. 20).
Jesus pointed out that the question of the place of worship would soon be a moot point (v. 21). Then, one could worship God in any place. What would matter is how one worships God (vv. 23-24).
Worship must harmonize with God, the very object of our worship. God is Spirit and thus our worship must harmonize with his nature. Likewise our worship must be in truth, thus harmonizing with God's own revelation.
1) Worship in Spirit. To worship God in spirit means to worship from the heart. Consider the use of "in the spirit" in Romans 2:28-29 - "For he is not a Jew who is one outwardly, nor is circumcision that which is outward in the flesh; but he is a Jew who is one inwardly; and circumcision is that of the heart, in the Spirit, not in the letter; whose praise is not from men but from God" (emphasis mine, DVR). Notice how that inwardly and of the heart are used synonymously with in the spirit.
Thus, to worship God in spirit is to worship sincerely, from the heart. Worship is far more than going through some outward motions. It involves keeping our thoughts on what we are doing and the meaning of what our actions are. Consider the quote from Albert Barnes: "A pure, a holy, a spiritual worship, therefore, is such as he seeks - the offering of the soul rather than the formal offering of the body - the homage of the HEART rather than that of the LIPS" (Barnes' Notes, Electronic Database. Copyright (c) 1997 by Biblesoft)
2) Worship in Truth. To worship God in truth means to worship in harmony with the truth that God has revealed (cf. John 17:17). If not, then we can do anything we want in worship!
All that we do in word or deed (which includes our worship) is to be in the name of Christ (Col. 3:17). To act in the name of Christ is to act by his authority (cf. Acts 4:7). Thus, every act of worship must be authorized by God.
If we go beyond the doctrine of Christ by offering worship that is not found in the word of truth, we are no longer in a right relationship with God (2 John 9).
3) Possible to Worship and Be Wrong. Since Jesus says that worship must be in spirit and in truth, then we must conclude that one could worship and his worship be wrong (Cf. Acts 17:23; Col. 2:23).
It is possible to worship God in truth (offer the scriptural acts) and yet our heart not be in what we are doing. Our minds may wander and thus what we offer is not sincere.
It is also possible to worship God in spirit (offer sincere worship from the heart) and yet our actions not be what God has authorized. May we strive to make our worship in spirit and truth.
- The Teacher, 9/8/13