Jesus came on earth with a mandate to set forth words among them that will believe him, and to die on the cross and raise on the third day to purchase the salvation of many. And all this was to begin with those who received his words.
The verse shows us that as he prayed, the final prayer; he declared that they had believed in the words which he taught them and that they had known beyond doubt that God had sent him. In this, he expressed that his disciples had discerned who he was and what he had come to accomplish.
God will never establish you in a purpose you have not discerned. Find me a man who is not making progress and I will show you a man who did not discern the word of God.
Always take time to study the mind of God concerning your life so that you can walk securely in his purpose. Knowing well that you have the faith and the approval of God Jehovah.
Heavenly Father, I thank you because you have revealed in me your word both to redeem and to build my life. AMEN