Here St. Thomas Aquinas comments on John 14:6 where Jesus says “I am the way, the truth and the life; no one comes to the Father but by me.”
Christ himself is the way, and therefore he says: I am the way. This certainly is eminently right for through him we have access to the Father.
Since this way is not separate from its end, but joined to it, he adds the truth and the life; thus he is himself at once both the way and the goal. In his human nature he is the way, and in his divine nature he is the goal. Therefore, speaking as man he says: I am the way; and speaking as God he adds: the truth and the life. These two words are an apt description of this goal.
For this goal is the object of human desire, and a man desires two things above all. In the first place he wants to know the truth, which is peculiar to him; and secondly he wants to continue to exist, which is common to all things. Christ is the way by which we come to know truth, though he is also that truth: Lead me, O Lord, in truth, and I shall enter into your way. Christ is also the way to come to life, though he is also that life: You have made known the ways of life.
Therefore, he designated the end of this way by truth and life, about which we have spoken above with reference to Christ. First, he himself is life, for life was in him; then, he is truth, because he was the light of men, and light is truth.
If, then, you are looking for the way by which you should go, take Christ, because he himself is the way: This is the way; walk in it. And Augustine says: Make man your way and you shall arrive at God. It is better to limp along the way than stride along off the way. For a man who limps along the way, even if he only makes slow progress, comes to the end of the way; but one who is off the way, the more quickly he runs, the further away is he from his goal.
If you are looking for a goal, hold fast to Christ, because he himself is the truth, where we desire to be. My mouth shall reflect on the truth. If you are looking for a resting place, hold fast to Christ, because he himself is the life. Whoever finds me finds life, and receives salvation from the Lord.
Therefore hold fast to Christ if you wish to be safe. You will not be able to go astray, because he is the way. He who remains with him does not wander in trackless places; he is on the right way. Moreover he cannot be deceived, because he is the truth, and he teaches every truth. And he says: For this I was born and for this I have come, to bear witness to the truth. Nor can he be disturbed, because he is both life and the giver of life. For he says: I have come that they may have life, and have it more abundantly (John 10:10).
This excerpt from the Exposition on John’s Gospel by St. Thomas Aquinas (Cap. 14, lect. 2) is a commentary on John 14:6 where Jesus says “I am the way, the truth and the life; no one comes to the Father but by me.” It is used in the Roman Office of Readings for Saturday of the ninth (9th) week in ordinary time with the accompanying biblical reading of Job 42:7-17.