According to Mosaic Law, testimony could not be given by one witness alone - "one witness alone shall not take the stand against a man in regard to any crime or any offense of which he may be guilty; a judicial fact shall be established only on the testimony of two or three witnesses."(Deuteronomy 19:15)
In this chapter of John, Jesus is basically establishing His credentials. He is telling us who He is, where He comes from, Who sent Him, and from where He gets His authority. In today's passage He even brings things down to a very human level. He goes out of His way to present His witnesses, those who can testify on His behalf and prove who He is.
Jesus goes above what is require by law and presents four witnesses -
John the Baptist, His miracles, His Father, and the Scriptures for His defense. John cried out, "Behold the Lamb of God who takes away the sins of the world", "I am not fit to loosen the thong on His sandal", and "I must decrease so that He may increase." John testified that Jesus was the "One who was to come."
Jesus' miracles testify to His authority, "Go and tell John what you hear and see: the blind receive their sight and the lame walk, lepers are cleansed and the deaf hear, and the dead are raised up, and the poor have good news preached to them."
The Father witnesses to Christ, "this is my beloved Son in whom I am well pleased."
Finally, the Scriptures attest to the authority of Jesus from Genesis onward.
Today these four witnesses still cry out to us. They take up the words of John the Baptist, "Behold the Lamb of God." Today, instead of the testimony of John, our human witness is the Pope and the Bishops pointing to Christ. Miracles happen even up to this moment, real, physical and spiritual miracles. Today, we see and hear the voice of the Father in all of creation, in His generosity, in His patience, in His constant call to "Listen to Him." The Scriptures too lead us to the authority of Christ and to his loving, transforming, power. The four witnesses still testify to this very moment.
What then, we may ask, stops us from accepting the witness presented to us? Why do we often not accept this testimony? In reading this passage we may be tempted to think of Jesus on the witness stand and we the prosecutor but that would mean we are more like Pilate than Christ. Rather it is we who are on the stand and depending on where we are in Christ, the four witnesses may testify against us or in our defense! We would do well to listen to the witnesses and believe their testimony now.
Jesus lists three things that keep us from believing the witnesses. The first stumbling block is a lack of love for God and His goodness. If we do not seek to love God who loves us more than we can ever fathom, then we will not believe those other three witness who exist because of His love. The second stumbling block is a preoccupation with the opinions of man. If we live in the minds of others, worrying what they think of us and our lives, we have no room nor time to consider the opinion of God. When we are so focused on ourselves and what others think of us the witnesses fade into the shadows. How many more miracles could Our Lord work, if we weren't afraid to acknowledge Him in the presence of others? The final stumbling block is a closed heart in the presence of the Living Word of God. If we do not approach the Scriptures with an open, child-like heart, we will never be able to hear or see the four witnesses to the authority of Jesus. "Indeed the word of the Lord is living and effective, sharper than any two-edged sword, penetrating even between soul and spirit, joints and marrow, and able to discern reflections and thoughts of the heart." (Hebrews 4:12)
Let us strive to seek out and believe the witnesses and seek to avoid the stumbling blocks.