What does worship "in spirit" and "in truth" mean?

What is the Lord contrasting in John 4: 23-24?

The Samaritan woman mentioned worship, pitting "this mountain" against Jerusalem, essentially saying, "That’s your religion; this is mine." The Lord then contrasted the revelation of God entrusted to the Jews with its absence among the Samaritans. Humanity must be enlightened by God in order to worship Him fittingly. "Ye worship ye know not what: we know what we worship" (verse 22). But the second movement of the Lord’s response addresses a void in both systems. Externalism, formalism, and ritualism must yield to worship from the spirits of men. Since God is spiritual in essence, He has been leading men from formal worship, as instituted under the Law, to the ultimate of His purpose, "true worshipers." In this age, the Father achieves an ultimate purpose in redemption: worshippers who worship in spirit and in truth. Believers now worship in the heavenly sanctuary and, by the power of the Spirit, their redeemed spirits ("in spirit") offer worship in keeping with the full revelation of all God is, as revealed in the Word ("in truth"). This transcends sacrifices and means of worship that are neither rational (able to know God) nor spiritual.

D. Oliver