Why Jesus Christ?
Jesus is the reason for creation to exist at all. Even before the foundation of the world God the Father planned that heaven and earth should be united in Jesus Christ, so he could give us all the blessings of heaven through him (Ephesians 1,1-10). Jesus is God in Person. He is God the Son who becomes man through the power of the Holy Spirit and the womb of the Virgin Mary. He is also fully human like us in every way, except for sin (which would make him less than human).
He taught that he came to bring "life and life to the full" (John 10,10) to anyone who accepts him. But because of original sin and the countless personal sins that also bring death to the soul, his life’s work became one of suffering, sorrow and rejection. On the cross he makes up for the selfishness of others with his selfless sacrifice of obedient love and he also apologizes to his Father for the infinite offence which sin gives to Divine Goodness.
When he rose from the dead he began a whole new life for human beings in God's grace. Those who belong to him in the Church through baptism are redeemed from original sin and born again as true children of God. Ultimately it is through Jesus that those who love him will see God as he really is and become utterly like him, so we can live the life of heaven together with Jesus in the indescribable joy of the Holy Spirit, which is what God the Father wants for us.