The authority of the Son comes from the Father. The Son does only the will of the Father. The Father loves the Son and shows him all that he himself is doing. The Father is the source of life and he is the life-giver. So the Son too gives life to all. The Sabbath works of Jesus is thus a way of giving life. When he healed the paralytic, he gifted him the same life because the Father has empowered him to do so. Only a further sin takes away this eternal life (Jn 5: 14).
The second action of Jesus is judgment. The Father has entrusted everything to him. The judgment is granting life in fullness because it is the vindication of the good. So Jesus saves through judgment. In as much as one has accepted Jesus and experienced life, the judgment confirms the decision and the consequent experience of life. Judgment in the Gospel of John has the implications of realized eschatology and final eschatology. Through faith in Christ salvation is experienced by a person already here on earth. This experience reaches the fullness in the final one. Thus what Jesus does on the Sabbath is the experience of realized eschatology.
In Jesus’ ministry the end of the age has been initiated. Its realized form is “already” here, but its final form is “not yet”. So Jesus can say, “…the hour is coming, now is, when the dead will hear the voice of the Son of God, and those who hear will live. …” (Jn 5: 25). Here, there is a shift from “Father-Son” language to “Son of Man” language. It is pertinent to note the parallelism between Daniel 12: 2 and John 5: 29.
Now, John 5 passes on to another phase. So far, Jesus has been speaking about himself. In the Jewish tradition self-testimony is not acceptable (Jn 5: 31; 8: 17). But witnesses are necessary. The Old Testament basis is Deuteronomy 19: 15 and Numbers 35: 30 are relevant too. Here, it has nothing to do with sentencing a person to death, but proving the truth of a claim. There is a broadening of the legal principle. Jesus is using a rabbinic way of argumentation for presenting his teaching further.
The witnesses to Jesus are: John the Baptist, Jesus’ works, the Father, and the Scriptures.