The Knowing of The Son

And the Father himself which hath sent me, hath borne witness of me. Ye have neither heard his voice at any time, nor seen his shape. And ye have not his word abiding in you; for whom he hath sent, him ye believe not.
— John 5:37-38

How is one to know that a thing is true? By doing what you know to be true, and calling nothing true until you see it to be true; by shutting your mouth until the truth opens it.  “But if I do not take the words attributed to him by the evangelists for the certain, absolute, very words of the Master, how am I to know that they represent his truth?” By seeing in them what corresponds to the plainest truth he speaks, and commends itself to the power that is working in you to make of you a true man; by their appeal to your power of judging what is true; by their rousing of your conscience. If they do not seem to you true, either they are not the words of the Master, or you are not true enough to understand them. Be certain of this, that if any words that are his do not show their truth to you, you have not received his message in them; they are not yet to you the word of God. They may be the nearest to the truth that words can come; they may have served to bring many into contact with the heart of God; but for you they remain as yet sealed. If yours be a true heart, it will revere them because of the probability that they are words with the meaning of the Master behind them. If you wait, your ignorance will not hurt you; if you presume to reason from them, you are a blind man disputing what you never saw. Humble mistake will not hurt us: the truth is there, and the Lord will see that we come to know it. The error of a true heart will not be allowed to ruin it. Certainly that heart would not have mistaken the truth except for the untruth yet remaining in it; but he who casts out devils will cast out that devil as well.