One grace converts Peter and leaves Simon Magus unconverted
Thesis II. They teach that God, so far as it rests with him, wants to convert everyone to whom the word is preached, and offers the same grace to all and to each. Many, however, resist divine grace and the Holy Spirit as he sets about the work of conversion, so in them grace does not achieve its effect. Others let divine grace in and put no obstacle in its way, and in them grace is efficacious and actually brings about conversion.
Since, on God's side, the grace that converted Simon Peter is the same grace that failed to convert Simon Magus, the difference being only that one resisted and the other did not, they see no reason to distinguish one grace from the other.
Latin
II. Quippe docent Deum omnes quibus verbum praedicatur, quantum in ipso est, velle convertere, & eandem omnibus & singulis offerre gratiam: Verum divinae gratiae & spiritui sancto conversionis opus aggredienti multos resistere: ac propterea gratiam effectum suum in illis non sortiri: alios vero divinam gratiam admittere, & non ponere ipsi impedimentum; unde fit ut gratia sit in ipsis efficax, & conversionem actu in illis efficiat. Sed quoniam ex parte Dei eadem gratia est quae Simonem Petrum convertit, & Simonem Magum non convertit, quoniam alter ipsi restitit, alter non restitit, idcirco unam ab alia non putant esse distinguendam.