When Jesus asked His disciples, "Who do people say that I am?," the disciples gave various answers that they'd heard bandied about. What do you think people's response is to that question today? Who do people say that Jesus is? You might hear answers like a wise man, a good person, a powerful preacher, a skilled teacher, a 1st century Jewish Rabbi, an historical figure. All of these are true of course, but these answers miss the mark. Others might say Jesus is a myth or fairy tale. The Jehovah's Witnesses would say that Jesus is "a god" but not the same as god as the Father. For them, Jesus is a created being. Mormons might say that Jesus is the brother of Lucifer who we know as the devil! Even some lifelong Christians from other churches don't understand the divinity of Jesus.
On Trinity Sunday we read the Athanasian Creed in our service. The focus of the Sunday is the doctrine of the Holy Trinity, but the Athanasian Creed also hammers home the point that Jesus is truly God. "We believe and confess that our Lord Jesus Christ, the Son of God, is at the same time both God and man." Or as we say in the Nicene Creed, Jesus is "of one substance with the Father." So we Christians can answer the question "Who is Jesus?" by responding that Jesus is the Son of God, truly God and truly man, our Savior.
Why does this matter? Sound doctrine isn't important just so we can be right. What we believe actually matters. What if Jesus weren't truly man? Well then, He wouldn't be one of us would he? He would have been a faker, an imposter. He wouldn't have experienced the temptation, the anguish, the sadness, and pain that we feel. In speaking of Jesus, the writer to the Hebrews says, "For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin" (Heb 4:15). What if Jesus weren't truly God? Well for one, that would make Him a liar since He repeatedly applied God's name to Himself (For example, in last Sunday's Gospel reading from John 8:58), and told the people that He and God the Father are one. And what of Christ's sacrificial death? A mere human's blood cannot cleanse the sin of another. But Jesus died as the God-man, the perfect, spotless, unblemished lamb of God. God the Son died on the cross, and God's blood does cleanse us from all sin. "In [Christ] we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace" (Eph 1:7). Thanks be to God for our Savior, true God and true man.