Far from borrowing concepts from other religions, as Ram Mohan Roy had done, Swami Dayananda was fiercely critical of Islam and Christianity as may be seen in his book Satyartha Prakasha. He was against what he considered to be the corruption of the pure faith in his own country. Unlike many other reform movements within Hinduism, the Arya Samaj's appeal was addressed not to the educated few but to the Indian nation as a whole.
The Arya Samaj unequivocally condemned idolatry, animal sacrifices, ancestor worship, pilgrimages, priestcraft, offerings made in temples, the caste system, untouchability and child marriages, on the grounds that all these lacked Vedic sanction. It aimed to be a universal "church" based on the authority of the Vedas.
Dayananda’s concept of Dharma is succinctly set forth in his Beliefs and Disbeliefs. He says "I accept as Dharma whatever is in full conformity with impartial justice, truthfulness and the like; that which is not opposed to the teachings of God as embodied in the Vedas. Whatever is not free from partiality and is unjust, partaking of untruth and the like, and opposed to the teachings of God as embodied in the Vedas - that I hold as adharma." Again he says "He, who after careful thinking, is ever ready to accept truth and reject falsehood; who counts the happiness of others as he does that of his own self, him I call just."