There are five branches of irreligion

                 SB 7.15.12

                                        vidharmaḥ para-dharmaś ca
                                        ābhāsa upamā chalaḥ
                                        adharma-śākhāḥ pañcemā
                                       dharma-jño ’dharmavat tyajet
                                           
                                               Word for word:
vidharmaḥ — irreligion; para-dharmaḥ — religious principles practiced by others; ca — and; ābhāsaḥ — pretentious religious principles; upamā — principles that appear religious but are not; chalaḥ — a cheating religion;adharma-śākhāḥ — which are different branches of irreligion; pañca — five; imāḥ — these; dharma-jñaḥ — one who is aware of religious principles; adharma-vat — accepting them as irreligious; tyajet — should give up.

                                Translation: 
There are five branches of irreligion, appropriately known as irreligion [vidharma], religious principles for which one is unfit [para-dharma], pretentious religion [ābhāsa], analogical religion [upadharma] and cheating religion [chala-dharma]. One who is aware of real religious life must abandon these five as irreligious.

                                Purport: 

Any religious principles opposed to the principle of surrendering to the lotus feet of the Supreme Personality of Godhead, Kṛṣṇa, are to be considered religious principles of irregularity or cheating, and one who is actually interested in religion must give them up. One should simply follow the instructions of Kṛṣṇa and surrender unto Him. To do this, of course, one needs very good intelligence, which may be awakened after many, many births through good association with devotees and the practice of Kṛṣṇa consciousness. Everything but the principle of religion recommended by Kṛṣṇa — sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja — should be given up as irreligion.

However, one should consider the following point.   Though it is worthless to criticize a difference in  religious system,  if one sees a fault, one should not tolerate it.   It is beneficial for the living entities if one   attempts to correct the fault in the proper way.   Thus Mahabprabhu, in discussing with Buddhists, Jains  and impersonalists, led them to the proper path.  The devotees of Lord Chaitanya should always take the  Lord's behavior as the proper example to follow.

The devotee does not accept those  religions which are filled with atheism, skepticism, materialism,  pantheism  and impersonalism  as real religions.  He knows them to be false religions, anti-religious  movements, perverted  religions, and he understands that their followers are unfortunate.  The devotees  must try to protect the living entities from these false religions.

Pure love is the eternal function of the soul.    Though the above mentioned five differences may exist in a  religion,  the  real religion is pure love.  This is the final goal of religion.  We should  not quarrel over  external differences.  If the goal of a religion is pure love, then all else is adjusted.  Atheism, skepticism, polytheism, materialism, pantheism, and impersonalism are, by their very nature, contrary to love.

Of all the conceptions of God existing in the world, the form of Krishna is the most suitable for developing  pure love.  The conception of Allah in the Koran is not suitable for developing pure love.  Even the Lord's  dear prophet  could not see Allah's form, for though the Lord is friendly, He remains at a distance from the  worshipper due to the conception of God as master.   The god in the Christian faith is also some  distant  entity, what to speak of the  impersonal Brahman.  Even Narayana is not the form by which the soul can  easily obtain pure love. Krishna alone, who resides in the spiritual abode of Vraja, is the object of pure love. 
                         Srila Bhaktivinode Thakur Chaitanya-siksamrita