Here is a little approach to Calvinist soteriology, made by none other than Leo the Great, a Bishop of Rome who would not have liked some of his successors.
Sermon 73, On Whitsuntide
As therefore we abhor the Arians, who maintain a difference between the Father and the Son, so also we abhor the Macedonians, who, although they ascribe equality to the Father and the Son, yet think the Holy Ghost to be of a lower nature, not considering that they thus fall into that blasphemy, which is not to be forgiven either in the present age or in the judgment to come, as the Lord says: �whosoever shall have spoken a word against the Son of Man, it shall be forgiven him, but he that shall have spoken against the Holy Ghost, it shall not be forgiven him either in this age or in the age to come.� And so to persist in this impiety is unpardonable, because it cuts him off from Him, by Whom he could confess: nor will he ever attain to healing pardon, who has no Advocate to plead for him. For from Him comes the invocation of the Father, from Him come the tears of penitents, from Him come the groans of suppliants, and �no one can call Jesus the Lord save in the Holy Ghost,� Whose Omnipotence as equal and Whose Godhead as one, with the Father and the Son, the Apostle most clearly proclaims, saying, �there are divisions of graces but the same Spirit; and the divisions of ministrations but the same Lord; and there are divisions of operations but the same God, Who worketh all things in all.�