ANSWER: Jesus made his comment about the need to worship our Father in spirit and truth when he talking to a Samaritan woman at the well of Jacob. In John the 4th chapter he tells the woman that God is seeking those who are willing to worship him "in spirit and in truth" (verse 23).
The Scriptures say that the Word of God is true (John 1:14) and that Jesus is Truth (Psalms 119:160; John 14:6) incarnate. It also states that the Bible is a lamp to guide the ways of a person (Psalms 119:105). Now that we know a little about truth, how do we combine it with the spirit in our worship?
We read in the Old Testament the specific details about what was required of the Priests and Levites before they could minister and worship before the Lord God. The Bible also tells us, however, that something changed when Jesus died on that stake 2,000 years ago. The veil in the Temple was torn from top to bottom when our Savior died, which meant that believers now had, in spirit, direct access to God.
In order to worship God properly we need to look at the spirit or spiritual meaning of the last six commandments. The fifth commandment states we are supposed to honor our mother and father. By doing this in the physical letter, we are also honoring God the Father as the ultimate parent of all mankind. Whom would you go to for advice? When you were little you went to your parents, but as you get older you go directly to the Father in Heaven.
The sixth commandment declares we are not to murder another human being. The spirit or intent of this commandment is that we should not even hate another human or hold a grudge. The seventh commandment states "in the letter of the law" that we are not to commit adultery. It's intent, however, means we are not to lust in our hearts for another person and to be faithful to our marriage partner.
The eighth commandment, which will also help us worship God in truth, states we are not to steal from one another. The intent of this law is that we should not even be taking another person's thoughts and use them as our own.
The ninth commandment declares we are not to bear false witness, which in the spirit means we are not to even exaggerate a story. The tenth, and last, commandment says we are not to covet what does not belong to us, which spiritually means we should be content with what we have already and be thankful for it.
The last six commandments are, sadly, not followed by the world. This means that when we seek to worship God IN SPIRIT and IN TRUTH we are going against everything around us. We cannot, on our own strength, do this unless the Spirit of God leads us and gives us the ability to accomplish this feat.
Our ultimate goal in life should be to "take captive" all of our thoughts until they are the same ones that Jesus would have (2Corinthians 10:3 - 6). The process of conversion is made possible through the death of Jesus. As we become more and more like our Savior, our worship becomes more meaningful and we have a closer relationship with our heavenly Father.
God is love and therefore would not make a law that is not for the ultimate good of mankind. We need to give God the Father and Jesus Christ the highest praise and honor in our worship with our whole heart and being. We need to obey every thing that comes from his mouth whether written or spoken. We need to be in a state of continual repentance for our erroneous thoughts and behavior once we understand that it is contrary to what is written in Scripture.
We are to give of ourselves joyously to help others come to the same understanding. We are to fellowship with those who are also being led by his Holy Spirit. We are also to conduct our lives to please God and take care of our bodies which are to be a living sacrifice to him (Romans 12:1). All this will greatly aid us to worship God both in spirit and in the truth.