Our Lord spoke of the Spirit as the Advocate or Paraclete (cf. John 14:16). This Advocate defends and intercedes. The Spirit testifies to the fact that our Lord will not leave us orphaned (cf. John 14:18). The Spirit assures us of God’s abiding presence in the Church. Why is this important? Because God knows that we need to hear the truth.
One of the many works of the Church is to preserve the teachings of our Lord Jesus Christ intact, whole and entire, without compromise. In other words, the Church must speak the truth. This is the work of the Spirit. Our Lord will say, “But when he comes, the Spirit of truth, he will guide you to all truth. He will not speak on his own, but he will speak what he hears, and will declare to you the things that are coming” (John 16:13). There is always a future dimension to the Spirit’s work, declaring “the things that are coming.”
Only God knows what will be. To have confidence now that what is happening will eventually accomplish the good that God intends is part of the faith and hope that a Christian is called to live. The Spirit’s work in us and in the Church is to build up that trust in God. That trust is rooted in the truth.
The measure of the truth that is revealed is found in Jesus Christ Himself. The Spirit of truth “will glorify me,” our Lord says, “because he will take from what is mine and declare it to you. Everything that the Father has is mine; for this reason I told you that he will take from what is mine and declare it to you” (John 16:14-15). The preservation of what God reveals, the Truth that He wants us to know, is the marvelous work of the Trinity.