Everything in Christianity centers on the incarnation of the Son of God, an invasion of God among men and women in time, bringing and working out a salvation not only understandable by them in their own historical and human life and existence, but historically and concretely accessible to them on earth and in time, in the midst of their frailty, contingency, relativity, and sin.
-T. F. Torrance
In other words,
That which was from the beginning, which we have heard, which we have seen with our eyes, which we looked upon and have touched with our hands, concerning the word of life—the life was made manifest, and we have seen it, and testify to it and proclaim to you the eternal life, which was with the Father and was made manifest to us—that which we have seen and heard we proclaim also to you, so that you too may have fellowship with us; and indeed our fellowship is with the Father and with his Son Jesus Christ. And we are writing these things so that our joy may be complete.
-1 John 1:1-4