Knowing all the theories about Jesus existence does not make us true. Many people confess their sins to Jesus and ask for forgiveness and receive Him as their Saviour and then all growth stops. They accept the one who is true but their quest for truth stops. Jesus is their foundation but they stop embracing Christ's character and work on the superstructure of their life stops. They do not put on the character of Christ.
Godly character is like a beautiful house build on a good foundation.
Its a credit to our designer, Jesus Christ. First, the truth of Jesus' virgin birth and death on the cross to pay the penalty for my sin means that I can have God's forgiveness and standing before the God of the universe. That great truth frees me in my spirit by removing the load of guilt that I had been carrying for my sinful attitudes and actions. When that happens I move closer to being a true person because I have embraced the truth of my need for the way, the truth and the life. Second, the wonderful truth of immortality impacts my life.