To remain a member of the Church is not proper for us

… we, as Baha'is, must not have any affiliations with churches or political parties. ... We, as Baha'is, can never be known as hypocrites or as people insincere in their protestations and because of this we cannot subscribe to both the Faith of Bahá'u'lláh and ordinary church dogma. The churches are waiting for the coming of Jesus Christ; we believe He has come again ... The churches teach doctrines - various ones in various creeds - which we as Bahá'ís do not accept... In other words there is no Christian church today whose dogmas we, as Bahá'ís can truthfully say we accept in their entirety - therefore to remain a member of the Church is not proper for us, for we do so under false pretences. …Very much the same reasons motivate us in withdrawing from all political movements, however close some of their ideals may be to ours.

(Shoghi Effendi, The Light of Divine Guidance, Vol. 1, p. 123)