There may be many who profess themselves as Christ’s disciples who are not his disciples indeed, but to earn recognition among others. Jesus assures them that their faith should abide in them, pass the test and produce obedience to His commandments and a holy life, it will be a proof that their faith is genuine, for the tree is known by its fruit.
Jesus gave those who believed in Him and continued in His word three promises. The first promise was assurance of salvation. For those who continue or abide in Christ’s word prove themselves to be His disciples. They live in His word and His word lives in them.
The second promise was that His disciples would “know the truth.” Truth is in Jesus. As Jesus said, “I am the way, and the truth, and the life. No one comes to the Father except through me” (John 14:6). Jesus also spoke of truth as part of the ministry of the Holy Spirit saying, “When the Spirit of truth comes, he will guide you into all the truth” (John 16:13)
The third promise Jesus gave was that the “truth will set you free.” Free from Sin’s bondage and sin’s penalty. Abiding in Christ’s word and knowing the truth, we are set free from our sin. The old sin nature is crucified, losing its power over us. And the penalty of sin, which is death is paid for according to the gospel truth– that Jesus paid the death penalty that we owed, so that we might receive eternal life. “John 8:31-32 Then said Jesus to those Jews which believed on him, If ye continue in my word, [then] are ye my disciples indeed; And ye shall know the truth, and the truth shall make you free.”