In the Age of Kali only one fourth of the religious principles remains. That last remnant will continuously be decreased by the ever-increasing principles of irreligion and will finally be destroyed.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
कलौ तु धर्महेतुनां तुर्यांशोऽधर्महेतुभिः । एधमानैः क्षीयमाणो ह्यन्ते सोऽपि विनङ्क्ष्यति
kalau tu dharmahetunāṃ turyāṃśo'dharmahetubhiḥ | edhamānaiḥ kṣīyamāṇo hyante so'pi vinaṅkṣyati
SB 12.3.24