This is reflected in the text of the so-called Nestorian Stele. Erected in 781, it was written by Jingjing, a monk whose Syriac name was Adam. The text is in both Chinese and Syriac and contains information about the structure of the Church of the East in China and its teachings. The excerpt below is found in Not of This World: A Treasury of Christian Mysticism, James S Cutsinger, ed, World Wisdom 2003, pp126-127.
In the beginning was the natural constant, the true stillness of the Origin, and the primordial void of the Most High. The Spirit of the void emerged as the Most High Lord, moving in mysterious ways to enlighten the holy ones. He is Ye Su, my True Lord of the Void, who embodies the three subtle and wondrous bodies, and who was condemned to the cross so that the people of the four directions might be saved.
He beat up the primordial winds, and the two vapors were created. He differentiated the gray emptiness and opened up the sky and the earth. He set the sun and moon on their course, and day and night came into being. He crafted the myriad things and created the first people. He gave to them the original nature of goodness and appointed them as guardians of all creation. Their minds were empty, they were content, and their hearts were simple and innocent. Originally they had no desire, but under the influence of Satan, they abandoned their pure and simple goodness for the glitter and the gold. Falling into the trap of death and lies, they became embroiled in the threee hundred and sixty-five forms of sin. In doing so, they have woven the web of retribution and have bound themselves inside it. Some believe in the material origin of things, some have sunk into chaotic ways, some think that they can receive blessings simply by reciting prayers, and some have abandoned kindness for treachery. Despite their intelligence and their passionate pleas, they have gone nowhere. Forced into the overturning wheel of fire, they are burned and obliterated. Having lost their way for eons, they can no longer return.
Therefore my Lord Ye Su, the One emanating in three subtle bodies, hid His true power, became a human, and came on behalf of the Lord of Heaven to preach the good teachings. A Virgin gave birth to the Sacred in a dwelling in the Western Empire. The message was given to the Persians, who saw and followed the bright light to offer Him gifts. The twenty-four holy ones have given us the teachings, and Heaven has decreed that the new religion of the Three-in-One Purity that cannot be spoken of should now be proclaimed. These teachings can restore goodness to sincere believers, deliver those living within the boundaries of the eight territories, refine the dust and transform it into truth, reveal the gate of the three constants, lead us to life, and destroy death. The teachings of the Religion of Light are like the resplendent sun: they have the power to dissolve the dark realm and destroy evil forever.
The Lord set afloat the raft of salvation and compassion so that we might use it to ascend to the palace of light and be united with the Spirit. He carried out the work of deliverance, and when the task was completed, He ascended to immortality in broad daylight. He left twenty-seven books of scriptures to inspire our spirit, He revealed the workings of the Origin, and He gave to us the method of purification by water. Thus we purify our hearts and return to the simple and natural Way of the truth. This truth cannot be named, but its power surpasses all expectations. When forced to give it a name, we call it the Religion of Light. As with the Way, that which is sacred is not sacred unless it is highly sacred, and that which is the Way is not the Way unless it is the Great Way.