In a sermon on Titus 3:4-7, John Calvin, Swiss Reformer of the 1500s, comments about how this passage teaches us both concerning the wellspring of our salvation, and the mean of our salvation, directing our faith completely to God in both matters.
Of the latter he says as follows,
"Whensoever we will find the mean of our salvation, we must begin at the Son of God. For it is he that hath reconciled us to God his father; it is he that hath washed us with his blood; it is he that hath purchased us righteousness by his obedience; it is he that is our advocate, and by whom we find grace at this day; it is he that bringeth us the Holy Ghost; it is he that hath gotten us the adoption whereby we be made the children and heirs of God. Wherefore let us note, that we must seek all the parts of our salvation in Jesus Christ: for we shall not find one drop of it any where else."