Back up that claim. With documentation please.
Here is just the tip of the iceberg- a smattering:
Papal Bulls
1184 “Ad abolendam”, by Pope Lucius III: The document prescribes measures to uproot heresy and sparked the efforts which culminated in the Albigensian Crusade and the Inquisitions. Its chief aim was the complete abolition of Christian heresy.
Lucius condemned all heretical sects and persons who preached without the authorisation of the Roman Church, whether publicly or privately, and placed them under excommunication. Among the particular sects mentioned in Ad abolendam were the Cathars, Humiliati, Waldensians, Arnoldists, and Josephines. More important than the direct attack on heresy, however, was the stipulation of equal measures for those who supported heretics, overtly or indirectly. They too were placed under excommunication.
Those accused of heresy, if they could not prove their innocence or forswear their errors, or if they backslid into error subsequently, were to be handed over to the lay authorities to receive their animadversio debita (“due penalty”). All those who supported heresy were deprived of their many rights: the right to hold public office, the right to trial, the right to draft a will, and the hereditability of their fiefs and offices.
For the enforcement of the measures demanded by the decretal, Lucius obligated all patriarchs, archbishops, and bishops to re-announce the excommunication on certain feasts and holidays. Those who did not observe this for three years consecutively would be deprived of their ecclesiastical offices. The bishops were furthermore obligated to “seek out” heretics. They were to make bi- or triannual rounds of their dioceses, visiting locations of suspicion and question the people about the existence of heresy. The people would be required to swear under oath (compurgation) anything they knew about heretical activity. All oath-breakers were to be treated as heretics.
The bull was incorporated as Canon 3 of the Fourth Council of the Lateran of 1215 under Pope Innocent III.
fordham.edu/halsall/basis/lateran4.asp
No forgiveness without repentance.
1145 “Quantum praedecessores”, Eugene III
1187 “Audita tremendi”, by Pope Gregory VIII
1198 “Post Miserabile”, by Pope Innocent III
1213 “Quia maior”, by Pope Innocent III
Calling for the Second, Third, Fourth, and Fifth Crusades. Why didn’t the Popes simply forgive the Muslims?
1199 “Vergentis in senium” by Pope Innocent III: Addressed to the city of Viterbo, announced that heresy would be considered, in terms of punishment, the same as treason. No forgiveness without repentance.
1215 Fourth Council of the Lateran, convoked by Pope Innocent III with the papal bull of April 19, 1213 (Just 1 example):
CANON 69
Since it is absurd that a blasphemer of Christ exercise authority over Christians, we on account of the boldness of transgressors renew in this general council what the Synod of Toledo (589) wisely enacted in this matter, prohibiting Jews from being given preference in the matter of public offices, since in such capacity they are most troublesome to the Christians. But if anyone should commit such an office to them, let him, after previous warning, be restrained by such punishment as seems proper by the provincial synod which we command to be celebrated every year. The official, however, shall be denied the commercial and other intercourse of the Christians, till in the judgment of the bishop all that he acquired from the Christians from the time he assumed office be restored for the needs of the Christian poor, and the office that he irreverently assumed let him lose with shame. The same we extend also to pagans. [Mansi, IX, 995; Hefele-Leclercq, III, 7.27. This canon 14 of Toledo was frequently renewed.]
fordham.edu/halsall/basis/lateran4.asp
No forgiveness without repentance.
1252 “Ad exstirpanda”, by Pope Innocent IV: Authorizes the use of torture for eliciting confessions from heretics during the Inquisition and executing relapsed heretics by burning them alive.
documentacatholicaomnia.eu/01p/1252-05-15,_SS_Innocentius_IV,Bulla%27Ad_Extirpanda%27,_EN.pdf
No forgiveness without repentance.
And then to jump ahead a bit just to mix it up (although there is much more from earlier as well. See:
1520 “Exsurge Domine” by Pope Leo X: Demands that Martin Luther retract 41 of his 95 theses, as well as other specified errors, within sixty days of its publication in neighbouring regions to Saxony. The following year there was “Decet Romanum Pontificem” that excommunicated him.
papalencyclicals.net/Leo10/l10exdom.htm
No forgiveness without repentance.
And there’s also the whole issue of Galileo:
en.wikipedia.org/wiki/Galileo_affair#Trial
No forgiveness without repentance.
I can provide many many more such examples, but these should suffice to those who are intellectually honest.
Are you?