"The Christian faith is ultimately not only a matter of doctrine or understanding or of intellect, it is a condition of the heart." That is a quote from the famous English preacher, Martyn Lloyd-Jones.
With all due respect to him whose writings years back helped me grow in my walk with the Lord, I would put it like this: that the Christian faith for each of us personally is ultimately about the truth of who Jesus is and how we respond to that truth.
Our heart condition will not grow in becoming what it needs to be unless we know the truth of Jesus — who he is and what he wants.
The early church went through greats pains to summarize the biblical teaching on the person of Jesus, and did so in what became known as the Nicene Creed. In reference to Jesus it reads that he was,
“…eternally begotten of the Father, God from God, Light from Light,
true God from true God, begotten, not made, of one Being with the Father.
Through him all things were made.”
Any definition of Jesus at odds with those affirmations gives us another Jesus, a demigod, that is, “a being with partial or lesser divine status.”
Consider this: when doubting Thomas came face to face with the risen Lord here’s what Thomas said to him: “My Lord and my God!” (John 20:28) First off, no Jew would ever refer to another Jew as his God. Such a statement would be so blasphemous that to say it would be beyond-the-pale unthinkable. But of equal importance is the fact that no Jewish rabbi or religious leader would ever for a split second allow himself to be referred to as “God.” That too would be so heinous as to warrant an all but violent rebuke.
However, Jesus accepted Thomas’ confession.
And if historical references to what subsequently happened to Thomas can be trusted, he went to India in 52 AD where he established seven church and where he was martyred in 72 AD. In other words, he lived a life devoted to the one to whom he said, “My Lord and my God.”
That affirmation embodied the truth of who Jesus was and Thomas believed that of Jesus. And Thomas’ response to that truth took over his whole life to the point of laying down his life for his Lord and God.
So I say, the Christian faith for us as well is ultimately about the truth of who Jesus is, and how we respond to that truth.