The second veil is Jesus, the truth. The third veil is Jesus, the life. Passing through to the Father involves experiencing Jesus in each of these measures. At first this may seem like a blessed experience to receive a further revelation of Christ. This word truth is better translated as reality.
Reality is experiential truth, or truth that is realized in our experience.
When we see Him, we also see ourselves. Then we are faced with the truth or reality about ourselves. In the year of King Uzziah's death, I saw the Lord sitting on a throne, lofty and exalted, with the train of His robe filling the temple. And the foundations of the thresholds trembled at the voice of him who called out, while the temple was filling with smoke. Then one of the seraphim flew to me, with a burning coal in his hand which he had taken from the altar with tongs.