Jesus said that true worshipers worship the Father in truth. What does it mean to worship the Father in truth? Let me suggest there are at least two answers to that question. The first is that true worshipers worship the Father in the truth about who He is. The second is that true worshipers worship the Father in the truth about who they are. Let’s look at the first one.
One of the early revelations God gave man of himself he gave to Moses.

And the Lord passed by before him (Moses) and proclaimed The Lord, the Lord God, merciful and gracious, long-suffering and abounding in goodness and truth, keeping mercy for thousands, forgiving iniquity and transgression and sin, by no means clearing the guilty, visiting the iniquity of the fathers upon the children and the children’s children to the third and fourth generation. So Moses made haste and bowed his head toward the earth and worshiped Him. (Exodus 34:6-8)

At various times throughout scripture God revealed himself to man. In the Psalms we can read many descriptions of God as man attempted to worship with the revelation God had granted. Yet, the ultimate revelation of God is seen in his Son. The writer of Hebrews tapped into this truth.

God, who at various times and in different ways spoke in times past to the fathers by the prophets, has in these last days spoken to us by his Son, whom he has appointed heir of all things, through whom also he made the worlds; who being the brightness of his glory and the express image of his person, and upholding all things by the word of his power when he had by himself purged our sins, sat down at the right hand of the Majesty on high.
(Hebrews 1:1)

Jesus was the express image of the Father. He gave us a perfect picture of what the Father is like. He never acted outside the Father’s directions and did only what he saw the Father doing. All the words Jesus spoke were in perfect harmony with God the Father. He told his disciples that he and the Father were one, and that whoever had seen him had seen the Father. Jesus never avoided making himself equal with God. In Philippians 2:6 Paul wrote speaking of Jesus, Who, being in the form of God, did not consider it robbery to be equal with God. Every attribute Jesus possessed is true of God the Father for he was God in the flesh.

Jesus spoke of his divinity, but many of the religious leaders did not accept it as truth. Jesus told the Jews, You search the Scriptures, for in them you think you have eternal life; and these are they which testify of me. (John 5:39) They called him a prophet and teacher but never worshiped him as God the Messiah, the Savior of the world.

So it is with many today. Many people say Jesus was a good man who did and said good things, but they deny his equality with God. To worship in truth is to worship God according to the truth he has revealed about himself, and he has perfectly revealed himself in and through his Son. John ended his gospel by saying that if the things Jesus did were written one by one that he supposed the world could not contain the books that would be written. I suppose that if all the attributes of God were written one by one the same would be true.

Until the truth God has revealed about himself through his word and his Son becomes truth that is written in our hearts, our worship will be stale and lifeless. This truth must be more than a head knowledge based on facts. It must also be truth written in our hearts, based on a relationship experience.

There is a story recorded in Matthew 15:21-28 and Mark 7:24-30 about a Greek woman, Syro-Phoenician by birth, who approached Jesus after he had entered the region of Tyre and Sidon. The woman followed Jesus and his disciples begging him to heal her daughter who had an unclean spirit. “O Lord, Son of David! My daughter is severely demon-possessed,” she cried. Jesus did not answer the woman immediately and was urged by his disciples to send her away. Jesus replied, “I was not sent except to the lost sheep of the house of Israel.” The woman then came and fell at Jesus feet, worshiped him and said, “Lord, help me!” Jesus answered her, “It is not good to take the children’s bread and throw it to the little dogs.” To which the woman replied, “True Lord, yet even the little dogs eat the crumbs which fall from their master’s table.” Jesus healed the woman’s daughter that very hour.

This woman must have heard the stories about people who had received healing by referring to Jesus as the Son of David: blind Bartimeus for one example. She knew that being a Gentile she had no claims on Jesus as the Son of David, but she was desperate to see her daughter healed. To get Jesus to hear her plea she pretended to have a relationship with him that did not exist. After the woman came to worship Jesus, he exposed her hypocrisy by calling her a dog. (It is interesting to note that the Greek word for worship used in this passage means to kiss the hand or lick like a dog.) This woman had now approached Jesus from the true position of her status and presented her plea. That was the approach which Jesus recognized.

Hebrews 10:22 says, Let us draw near to God with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience and our bodies washed with pure water. True worship flows from a true relationship with God. One can use the expressions of worship used by others, but if their relationship with God is not based on truth, it will not be true worship. Psalm 15:1-2 reads, Lord, who may abide in your tabernacle? Who may dwell in your holy hill? He who walks uprightly and works righteousness and speaks the truth in his heart. God said of Israel, These people draw near to me with their mouths and honor me with their lips but have removed their hearts far from me, and their fear toward me is taught by the commandment of men. (Isaiah 29:13)

To worship in truth means that what we speak with our lips is supported by how we live our lives. Israel talked the talk but did not walk the walk. Their experience with God was based on what was told them about God. They acknowledged that there was a God and that everything that was said about him was true. They even had religious ceremonies to honor him, but they had not given him their hearts. They came to God based on the experience of another, which made their worship futile.

In the book of Amos we read where God says to Israel that he hates and despises their feast days and sacred assemblies. He said that he did not accept their offerings and told them to remove the noise of their music and songs because he wasn’t listening. God is not impressed with our methods of worship if those methods express someone other than who we really are. God desires truth in the inward parts. When with a right relationship with God we come to him in worship, he hears. When he hears, he responds.