6:64

Jesus knew . . . the one who would betray him: Jesus was referring to Judas Iscariot. Jesus spent the entire night in prayer to his Father before selecting the 12 apostles. (Lu 6:12-16) So at first, Judas was faithful to God. However, Jesus knew from Hebrew Scripture prophecies that he would be betrayed by a close associate. (Ps 41:9; 109:8; Joh 13:18, 19) When Judas started to go bad, Jesus, who could read hearts and thoughts, detected this change. (Mt 9:4) By use of his foreknowledge, God knew that a trusted companion of Jesus would turn traitor. But it is inconsistent with God’s qualities and past dealings to think that Judas had to be the one who would fail, as if his failure were predestined.

from the beginning: This expression does not refer to Judas’ birth or to his being selected as an apostle, which happened after Jesus had prayed the entire night. (Lu 6:12-16) Rather, it refers to the start of Judas’ acting treacherously, which Jesus immediately discerned. (Joh 2:24, 25; Re 1:1; 2:23; see study notes on Joh 6:70; 13:11.) This also shows that Judas’ actions were premeditated and planned, not the result of a sudden change of heart. The meaning of the term “beginning” (Greek, ar·kheʹ) in the Christian Greek Scriptures is relative, depending on the context. For example, at 2Pe 3:4, “beginning” refers to the start of creation. But in most instances, it is used in a more limited sense. For instance, Peter said that the holy spirit fell on the Gentiles “just as it did also on us in the beginning.” (Ac 11:15) Peter was not referring to the time of his birth or to the time when he was called to be an apostle. Rather, he was referring to the day of Pentecost 33 C.E., that is, “the beginning” of the outpouring of holy spirit for a specific purpose. (Ac 2:1-4) Other examples of how the context affects the meaning of the term “beginning” can be found at Lu 1:2; Joh 15:27; and 1Jo 2:7.