How do we know that Judas was lost?

The identification of Judas as the 'son of perdition' is a critical aspect of understanding his character and fate. In John 17:12, Jesus explicitly distinguishes Judas from the rest of His disciples, noting that none of those whom He was given by the Father were lost except for Judas. This terminology permeates the biblical narrative surrounding Judas, emphasizing that his betrayal was foretold in Scripture and part of God's sovereign plan. Additionally, the New Testament passages consistently depict his actions as those of an unredeemed individual, one who followed Christ outwardly but lacked true faith and love for the Lord. Thus, his ultimate fate serves as a cautionary tale about the nature of authentic faith versus mere association with Christ.