While teaching topics of spiritual knowledge to both the students and teachers of the mundane schools of Navadvipa, Sri Gaurasundara composed the first verse of Sikshahstaka
anandambhudhi-vardhanam prati-padam purnamritasvadanam
sarvatma-snapanam param vijayate shri-krishna-sankirtanam
Glory to the Shri Krishna sankirtana (congregational chanting of the Lord's holy names), which cleanses the heart of all the dust accumulated for years and extinguishes the fire of conditional life, of repeated birth and death. That sankirtana movement is the prime benediction for humanity at large because it spreads the rays of the benediction moon. It is the life of all transcendental knowledge. It increases the ocean of transcendental bliss, and it enables us to fully taste the nectar for which we are always anxious.
In the second verse of Sikshashtaka there is an elaboration of the first.
namnam akari bahudha nija-sarva-shaktis
tatrarpita niyamitah smarane na kalaha
etadrishi tava kripa bhagavan mamapi
durdaivam idrisham ihajani nanuragahah
O my Lord, Your holy name alone can render all benediction to living beings, and thus You have hundreds and millions of names, like Krishna and Govinda. In these transcendental names, you have invested all Your transcendental energies. There are not even hard and fast rules for chanting these names. O my Lord, out of kindness You enable us to easily approach you by Your holy names, but I am so unfortunate that I have no attraction for them.
In the third verse the Lord reveals to the world the method of properly serving the first verse.
trinad api sunicena
taror api sahishnuna
kirtaniyah sada harihi
One should chant the holy name of the Lord in a humble state of mind, thinking oneself lower than the straw in the street; one should be more tolerant than a tree, devoid of all sense of false prestige, and should be ready to offer all respect to others. In such a state of mind one can chant the holy name of the Lord constantly.
In the fourth verse Sri Gaurasundara describes the process for giving up desires that are not related to Krishna.
na dhanam na janam na sundarim
kavitam va jagad-isha kamaye
mama janmani janmanishvare
bhavatad bhaktir ahaituki tvayi
O almighty Lord, I have no desire to accumulate wealth, nor do I desire beautiful women, nor do I want any number of followers. I only want your causeless devotional service, birth after birth.
In the fifth verse the Lord describes giving up realization of the Supreme Lord's opulences while worshipping the supremely blissful Absolute Truth and chanting the holy names as an eternal servant.
ayi nanda-tanuja kinkaram
patitam mam vishame bhavambudhau
kripaya tava pada-pankaja-
O son of Maharaja Nanda [Krishna], I am Your eternal servitor, yet somehow or other I have fallen into the ocean of birth and death. Please pick me up from this ocean of death and place me as one of the atoms at Your lotus feet.
The reactions of the body, mind, and speech as one progresses in chanting the holy names are described in the sixth verse.
vadanam gadgada-ruddhaya gira
pulakair nichitam vapuh kada
tava nama-grahane bhavishyati
O my Lord, when will my eyes be decorated with tears of love flowing constantly when I chant Your holy name? When will my voice choke up, and when will the hairs of my body stand on end at the recitation of Your name?
According to the consideration in the seventh verse that the holy names and the Lord are non-different, a practitioner achieves perfection by attaining the state of apana-dasa, realization of one's original constitutional position.
shunyayitam jagat sarvam
O Govinda! Feeling Your separation, I am considering a moment to be like twelve years or more. Tears are flowing from my eyes like torrents of rain, and I am feeling all vacant in the world in Your absence.
Lord Gaurasundara taught the eighth verse so that the same practitioner could become decorated with all symptoms of complete surrender by freeing himself from the bad association of aversion to Hari while giving up the concept of enjoyment in the course of chanting the holy names and thus attain Krishna prema.
ashlishya va pada-ratam pinashtu mam
adarshanan marma-hatam karotu va
yatha tatha va vidadhatu lampato
mat-prana-nathas tu sa eva naparaha
I know no one but Krishna as my Lord, and He shall remain so even if He handles me roughly by His embrace or makes me brokenhearted by not being present before me. He is completely free to do anything and everything, for He is always my worshipful Lord, unconditionally.
Other than this, Lord Gaurasundara forbade all of His beloved devotees from discussing any topics indirectly related to Krishna. The living entities bereft of Sri Krishna Caitanyacandra's affection do not accept the Supreme Lord, who is full of transcendental rasa, as their beloved, because their hearts are dry and hard. No one other than svayam-rupa Krishna is bold enough to impart such instructions.
Purport by His Divine Grace Srila Bhaktisiddhanta Saraswati Takur Prabhupada
Sri Chaitanya Bhagavata, Madhya Kanda, part three, chapter twenty eight text 27, page 530-31