How do we know that Christ's prayer is for the elect?

In John 17:9, Jesus clearly delineates the focus of His prayer as being for His disciples and, by extension, for all believers who will come to faith through their testimony. This highlights a specific intercessory role that Jesus fulfills as our High Priest, praying for the specific group of the elect rather than for the world at large. This distinction illustrates the biblical understanding of God's choice in salvation, affirming that Christ's redemptive work is effectively for His elect people, those chosen by God to receive mercy.