A large-scale and comparatively rapid change in the religious identity of the Albanians, especially in the mountain rural communities, was in progress in the mid- and late 17th century and, with varying intensity, during the 18th century. In a sense, the abandonment of Catholicism and the Orthodox faith by the Albanians was formal and employed as a conscious strategic move aiming at their survival and admittance to the hierarchy of the local Ottoman administration. Furthermore, this explains the presence of dual religious identity among the Gegs, but also among the Tosks in the South. Crypto-Christian behaviour was characteristic of the Albanian territories in the period from the 17th up to the late 19th century. In order to evade interference by the Ottoman administration in their home affairs, in their austere clan traditions of hierarchy and communal self-government, many Albanian clans, especially among the mountaineers in the North, adopted Islam formally and lived as dual-faith believers, just as in the description given by Lady Montagu. Along with the new religion they continued to celebrate the old Christian festivals and saints, baptised their children, took Holy Communion, married Christian women, practices strictly forbidden by the Sheriat prescriptions. Bishop Zmajevi? established that "there is a vicious and disdainful custom to give Holy Communion to those who, in order to evade taxation, publicly profess Mohammedanism, and secretly - the Christian faith, infecting others by their example…"⁷⁰  It is difficult to determine the role of the Catholic and Orthodox priests as shepherds of their flock, when the latter adopted Islam or sank into practising dual faith. According to M. Drinov's remarks, based on correspondence of Catholic envoys from their Albanian missions, the level of performance of the Catholic priests was extremely inadequate and they were often the first to adopt Islam and lead their flocks into conversion. Catholic priest Stefan Gaspari toured the Albanian eparchies in 1671-1672 and wrote that "the unworthy Catholic priests had not only been unable to maintain the faith in their flock, but also had utterly exterminated it by their foul life." In the eparchy of Dra? [modern Durrës] he met many Crypto-Christians, designated in the original by the Latin term of christiani occulti, who "overtly professed the Mohammedan faith, and secretly attended church to pray, confess their sins and take Holy Communion".⁷¹
Other scholars, like A. Zhelyazkova, to a degree P. Bartl and St. Skendi, hold the thesis that the local Catholic priests were closely linked with or were part of the family and clan ties in the highland communities and made efforts to be of service to their congregation. When, towards the middle of the 18th century, Pope Benedict XIV demanded in a special bull that the renegades, observing in secret the faith of their ancestors, should renounce Islam in public and profess Christianity openly, the population offered violent resistance to it, fully supported by their clerics.⁷²

As for the Orthodox priests, they were not only notorious for their ignorance, but also for the abuse of church tax collection. Besides, both the Catholic and the Orthodox population were levied with special taxes and duties. Since the time of Sultan Mehmed II, with the integration of the Orthodox Church in the system of the central Ottoman power, the Greek Patriarchate of Constantinople exacted a heavy fiscal regime on all Christians. Part of the church taxes were collected with a view of paying out what was known as peshkesh - a sum contributed by the Greek patriarchs to the state treasury in return for their right to be assigned to their position with an official document (berat). Along with these sums, the size of which was constantly growing, the Orthodox population gave also ecclesiastical miri rüsüm, comprising taxes and duties received by the metropolitans from the eparchies under their jurisdiction. There were a great number of other taxes collected on a voluntary or compulsory basis. Their collectors acted with the assistance and under the protection of the local Ottoman administrative bodies, usually bribed to turn a blind eye to malpractice.