9 That, moreover, is absurd, that they do not think it is to be inquired who was the person that baptized, for the reason that he who has been baptized may have obtained grace by the invocation of the Trinity, of the names of the Father, and of the Son, and of the Holy Ghost. Then this will be the wisdom which Paul writes is in those who are perfected. But who in the Church is perfect and wise who can either defend or believe this, that this bare invocation of names is sufficient to the remission of sins and the sanctification of baptism; since these things are only then of advantage, when both he who baptizes has the Holy Spirit, and the baptism itself also is not ordained without the Spirit?
But, say they, he who in any manner whatever is baptized without, may obtain the grace of baptism by his disposition and faith, which doubtless is ridiculous in itself, as if either a wicked disposition could attract to itself from heaven the sanctification of the righteous, or a false faith the truth of believers. But that not all who call on the name of Christ are heard, and that their invocation cannot obtain any grace, the Lord Himself manifests, saying, “Many shall come in my name, saying, I am Christ, and shall deceive many.” Because there is no difference between a false prophet and a heretic. For as the former deceives in the name of God or Christ, so the latter deceives in the sacrament of baptism. Both strive by falsehood to deceive men's wills.
Source: The Epistles of Cyprian (New Advent)