And didn’t the church teach that buying indulgences forgave sin?
Selling indulgence is simony. Second, do you know what indulgence is?
Here is a hint:
Indulgence is the full or partial remission of temporal punishment due for sins which have already been forgiven. The indulgence is granted by the church after the sinner has confessed and received absolution. The belief is that indulgences draw on the storehouse of merit acquired by Jesus’ sacrifice and the virtues and penances of the saints. They are granted for specific good works and prayers.
It was illegal during Martin Luther’s time to sell indulgence. The Council of Trent condemned the selling of Indulgence.
Actions for which indulgences are granted
There are four general grants of indulgence, which are meant to encourage the faithful to infuse a Christian spirit into the actions of their daily lives and to strive for perfection of charity. These indulgences are partial, and their worth therefore depends on the fervour with which the person performs the recommended actions:
Raising the mind to God with humble trust when performing one’s duties and bearing life’s difficulty, and adding, at least mentally, some pious invocation.
Devoting oneself or one’s goods compassionately in a spirit of faith to the service of one’s brothers and sisters in need.
Freely abstaining in a spirit of penance from something licit and pleasant.
Freely giving open witness to one’s faith before others in particular circumstances of everyday life.
Among the particular grants, which, on closer inspection, will be seen to be included in one or more of the four general grants, especially the first, the Enchiridion Indulgentiarum draws special attention[15] to four activities for which a plenary indulgence can be gained on any day, though only once a day:
Adoration of Jesus in the Eucharist for at least half an hour.[16]
The pious exercise of the Stations of the Cross .[17]
Recitation of the Rosary or the Akathist in a church or oratory, or in a family, a religious community, an association of the faithful and, in general, when several people come together for an honourable purpose.[18]
Piously reading or listening to Sacred Scripture for at least half an hour.[19]
A plenary indulgence may also be gained on some occasions, which are not everyday occurrences. They include:
Receiving, even by radio or television, the blessing given by the Pope Urbi et Orbi (to the city of Rome and to the world) or that which a bishop is authorized give three times a year to the faithful of his diocese.[20]
Taking part devoutly in the celebration of a day devoted on a world level to a particular religious purpose.[21] Under this heading come the annual celebrations such as the World Day of Prayer for Priestly and Religious Vocations, and occasional celebrations such as World Youth Day.[22][23]
Taking part for at least three full days in a spiritual retreat.[24]
Taking part in some functions during the Week of Prayer for Christian Unity including its conclusion.[25]
The prayers specifically mentioned in the Enchiridion
Indulgentiarum are not of the Latin Rite tradition alone, but also from the traditions of the Eastern Catholic Churches, such as the Akathistos, Paraklesis, Evening Prayer, and Prayer for the Faithful Departed (Byzantine), Prayer of Thanksgiving (Armenian), Prayer of the Shrine and the Lakhu Mara (Chaldean), Prayer of Incense and Prayer to Glorify Mary the Mother of God (Coptic), Prayer for the Remission of Sins and Prayer to Follow Christ (Ethiopian), Prayer for the Church, and Prayer of Leave-taking from the Altar (Maronite), and Intercessions for the Faithful Departed (Syrian).
Apart from the recurrences listed in the Enchiridion, special indulgences are granted on occasions of special spiritual significance such as a Jubilee Year[26] or the centenary or similar anniversary of an event such as the apparition of Our Lady at Lourdes[27] or the celebration of a World Youth Day.
Of particular significance is the plenary indulgence attached to the Apostolic Blessing that a priest is to impart when giving the sacraments to a person in danger of death, and which, if no priest is available, the Church grants to any rightly disposed Christian at the moment of death, on condition that that person was accustomed to say some prayers during life. In this case the Church itself makes up for the three conditions normally required for a plenary indulgence: sacramental confession, Eucharistic communion and prayer for the Pope’s intentions