Elsewhere in John's Gospel we read: "Ye shall know the truth and the truth shall make you free," (John 8:32) "and the spirit of truth shall guide you into all truth."(John 16:13).
When one is guided into all truth it is that God, by His Spirit has revealed the word of God to his heart. When the word of God comes in a saving manner it first makes known our condition before God that all have sinned and come short of the glory of God. (Romans 3:23). To read the scriptures or hear them faithfully preached and not become conscious of our sinnership before God means that it has not been profitable to our souls.
When it pleases God to send His word with power into our hearts then we cry with the psalmist: "Against thee, thee only have I sinned," (Psalm 51:4), for by the law is the knowledge of sin. (Romans 3:20). We are living in a day when truth is not desired. We could take up the words of the prophet Isaiah: Truth is fallen in the street and equity cannot enter. (Isaiah 59:14).
It is a day of campaigns and missions. We have professions and decisions but if one was to speak of the truths of the gospel experimentally known in the heart many would ask the question with ungodly Pilate, WHAT IS TRUTH?
This is why the Church has lost her defence: if the whole counsel of God is not declared true conversion cannot take place, then it is an outward profession with no inward possession. "She is tossed to and fro and carried about with every wind of doctrine."(Ephesians 4:14)
As we read the history of the Christian Church we come to know about the great battles that were fought for truth and of the sufferings and death when rivers of blood flowed from the veins of the saints and martyrs of Jesus. Why? Because they knew the truth and the truth had made them free (John 8:32) and they were determined not to be entangled again in the yoke of Romish bondage.
When Hugh Latimer was going to the stake he said it was because he would not go amassing: to go to mass would have been to deny the truth. During mass a Roman priest would claim the power to bring Christ from His exalted position on His Father's throne, King of Zion, and offer Him again on the Roman altar for the sins of the quick and the dead - O what blasphemy! But the truth had come to the reformer that this man (Jesus Christ) after He had offered one sacrifice for sins for ever, sat down on the right hand of God (Hebrews 10:26).
O that the truth of the gospel was again proclaimed in the power of the Holy Spirit and that people would come to a knowledge of the truth. Then with Paul they would say: "For I know in whom I have believed and am persuaded that He is able to keep that which I have committed unto Him against that day." (1 Timothy 1:12).
And this one he knew and believed in was Christ Jesus, who came into the world to save sinners, Paul himself, confessing to be the chief, (1 Timothy 1:15).
And Christ declares in His word: I am the way, the truth and the life, no man cometh unto the Father but by me ( John 14:6).