Joseph Smith restored many aspects of the original Christian church which he likely would not have known about on his own.
John W. Welch notes:
A volume of Gnostic writings from early Christianity, newly translated by Bentley Layton, was published in 1987 by Doubleday. It gives many texts analyzed several years ago by Hugh Nibley in The World and the Prophets and Since Cumorah, showing ways in which early Christian doctrines changed under the influences of Hellenistic philosophy and mystic religion.1 Today there is considerable evidence that secret and sacred covenants of early Christianity were lost early. Baptism for the dead, the use of prayer circles, and the sacrament itself underwent transformation, if not elimination. Similarly, asceticism and celibacy entered Christianity at an early stage to distort the meaning of the covenant of marriage and many passages in the Bible– John W. Welch – The Plain and Precious Parts
Where would Joseph Smith have gotten the idea of prayer circles from?