In the Atharva Veda, the Supreme Personality of Godhead Himself says:
"Towards the end of the period between four-thousand to five-thousand years in Kali-yuga, I will descend on the earth as Gauranga, a golden-complexioned saintly brahmana in a place by the Ganges' shore and later become the crest-jewel of all sannyasis, exhibiting all My transcendental qualities including supreme renunciation and complete detachment from material desires. In the form of Lord Gauranga, I will display all the thirty-two bodily symptoms of a great personality with my arms extending to my knees. I will become my own devotee, very advanced in bhakti-yoga and teach the worship of Lord Krishna (Myself) by the chanting of My own holy names and relishing the mellows of My own devotional service. At that time only My most confidential devotees will be able to understand Me."
"The Supreme Personality of Godhead, who appeared in Satya-yuga as Lord Nrisimhadeva in the form of half-man and half-lion to destroy Hiranyakasipu, the king of the demons, and who appeared in Treta-yuga as Lord Ramacandra to kill the great ten-headed demon Ravana, and who appeared in the Dvapara-yuga for protecting and maintaining the cowherd men and women of Vrindavana and removing the burden of the earth, will appear again in the Kali-yuga in a golden form. He will fully relish the chanting of His own holy names and His name will be Lord Gauranga."
"His limbs will be golden and His voice deep. He will increasingly hanker to taste the nectar of His own holy names and will be completely enchanted by it . He will be the most merciful son of Shrimati Sacidevi and His Name will be Gauranga."
"With great devotion and folded hands, one should recite the following prayer before Lord Gauranga, whose limbs are as effulgent as molten gold: 'I offer my respectful obeisances to Lord Gauranga-Krishna, the the son of the Nanda Maharaja and the elder brother of Gada.'"
In the Brahma Purana, the Supreme Lord Himself dnlares:
"In the first sandhya of Kali-yuga, I will appear as Gauranga on the earth in a beautiful place by the shore of the Ganges (*Navadvipa). I will descend in My original eternal form and My complexion will be golden."
"Lord Anantadeva, the upholder of the whole universe then which a chocked voice full of ecstasy tried to satisfy the Supreme Personality of Godhead Lord Shri Gauranga Mahaprabhu, the Supreme Cause of all Causes who possesses a transcendental eternal form of truth, knowldge and bliss."
The Lord said:"When I will appear in Kali Yuga, My transcendental names will be: Gauranga, Krishna Chaitanya, Gaurachandra, Shachisuta, Mahaprabhu, Gaura, Gaurahari. etc. Chanting These supreme Names will bring devotion to Me."
vrindavane navadvipe, bheda-buddhis ca yo narah; tam eva radhika-krishne, shri-gaurange paratmani.
mac-chala-pata-nirbhinna-dehah so 'pi naradhamah; pacyate narake ghore, yavad ahuta-samplavam.
Lord Shiva said: "With my trident I will cut into pieces anyone who thinks that Vrindavana and Navadvipa are different, or that Radha-Krishna and Gauranga are different, or that Lord Gauranga is not the Supreme Personality of Godhead. Such a person is most degraded among human beings. He or she will burn in a terrible hell until the time when the universe is flooded with water."
ya eva bhagavan krishno, radhika-prana-vallabhah; shrishtyadau sa jagannatho, gaura asin mahesvari.
"O Maheshwari Parvati, the Supreme Personality of Godhead Lord Krishna who is most dear to His Supreme consort Shrimati Radharani and who is known as Lord Jagannatha from the beginning of creation has Himself fully and personally advented in this Kali Yuga as Lord Shri Gauranga Mahaprabhu."
"Please hear attentively, I will describe in detail this most confidential secret. The Supreme Ishvara or Controller Lord Krishna who is the origin of everything is known and worshiped by the learned Vaishnava devotees as Lord Gauranga, when He accepts the golden complexion of Shrimati Radhika."
"I offer my prostrated obeisances to Adideva, the Supreme Lord Shri Gauranga Mahaprabhu who is the ultimate and original cause of all causes, the Paratma or Supersoul of all living entities and who possesses a transcendental eternal form of truth, knowldge and bliss."
"Those Vaishnava devotees who are Mahamati or very very advanced and who have accumulated spiritual piety for a minimum of 10 millions kalpas (1 kalpa = 8,640,000,000 years) will develop a superior taste for the transcendental pastimes of Their Lordships Shri Shri Radha Krishna."
"In this way those exalted devotees who have developed unflinching attachment (parama matih) for the transcendental pastimes of Their Lordships Shri Shri Radha Krishna are worshipable even by the greatest demigods and are known as jivanamukta or fully liberated souls."
vina shri-gopika-sangam, kalpa-koti-satam param; sravanat kirtanad vishnor, na radha-krishnam apnuyat.
Now the method to achieve Their Lordships Shri Shri Radha Krishna is described by Lord Shiva, "If someone does not serve and associate with the Gopies of Vrindavana, they will not achieve Radha-Krishna even if simply hear and chant about Lord Vishnu for a minimum of 1 billion kalpas (1 kalpa = 8,640,000,000 years)."
"And to achieve the service and association of the Gopies of Vrindavana the only way is to worship the lotus of Lord Gauranga and chant His Name. Therefore Parvati, you should worship Lord Gauranga and chant His Name constantly and with sarva-bhava means by full surrender and giving everything to Him."
"The person who is like a transcendental honeybee relishing the supreme ambrosial nectar (makaranda) emanating from the divine lotus feet of Lord Gauranga Mahaprabhu will most certainly without a doubt attain Their Lordships Shri Shri Radha Krishna even without performing any sadhana-bhakti practice of bhakti-yoga.
"The Supreme Personality of Godhead Lord Krishna who is most dear to His Supreme consort Shrimati Radharani is situated in Navadvipa in His transcendental combined form of Shrimad Gauranga to fulfil the innermost desires of His most intimate devotees."