The Confidential Reasons for the Lord's Appearance

CC Adi 4.16
The Lord’s desire to appear was born from two reasons:

•  the Lord wanted to taste the sweet essence of the mellows of love of God,
•  and He wanted to propagate devotional service in the world on the platform of spontaneous attraction.   

 
CC Ādi 4.230 "Desiring to understand the glory of Rādhārāṇī’s love, the wonderful qualities in Him that She alone relishes through Her love, and the happiness She feels when She realizes the sweetness of His love, the Supreme Lord Hari, richly endowed with Her emotions, appeared from the womb of Śrīmatī Śacī-devī, as the moon appeared from the ocean.”



From the Introduction to Adi Chapter 4- 3 reasons for the Lord's appearance

In this chapter of the epic Caitanya-caritāmṛta, Kṛṣṇadāsa Kavirāja Gosvāmī has stressed that Lord Caitanya appeared for three principal purposes of His own. 

1. The first purpose was to relish the position of Śrīmatī Rādhārāṇī, who is the prime reciprocator of transcendental love of Śrī Kṛṣṇa. Lord Kṛṣṇa is the reservoir of transcendental loving transactions with Śrīmatī Rādhārāṇī. The subject of those loving transactions is the Lord Himself, and Rādhārāṇī is the object. Thus the subject, the Lord, wanted to relish the loving mellow in the position of the object, Rādhārāṇī.
2. The second reason for His appearance was to understand the transcendental mellow of Himself. Lord Kṛṣṇa is all sweetness. Rādhārāṇī’s attraction for Kṛṣṇa is sublime, and to experience that attraction and understand the transcendental sweetness of Himself, He accepted the mentality of Rādhārāṇī.
3. The third reason that Lord Caitanya appeared was to enjoy the bliss tasted by Rādhārāṇī. The Lord thought that undoubtedly Rādhārāṇī enjoyed His company and He enjoyed the company of Rādhārāṇī, but the exchange of transcendental mellow between the spiritual couple was more pleasing to Śrīmatī Rādhārāṇī than to Śrī Kṛṣṇa. Rādhārāṇī felt more transcendental pleasure in the company of Kṛṣṇa than He could understand without taking Her position, but for Śrī Kṛṣṇa to enjoy in the position of Śrīmatī Rādhārāṇī was impossible because that position was completely foreign to Him. Kṛṣṇa is the transcendental male, and Rādhārāṇī is the transcendental female. Therefore, to know the transcendental pleasure of loving Kṛṣṇa, Lord Kṛṣṇa Himself appeared as Lord Caitanya, accepting the emotions and bodily luster of Śrīmatī Rādhārāṇī.

Lord Caitanya appeared in order to fulfill these confidential desires, and also to preach the special significance of chanting Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare and to answer the call of Advaita Prabhu. These were secondary reasons.

Knowing Krsna's Transcendental Nature Protects One from Material Contamination

SP purport to CC Adi 4.35

One who has not been attracted by the transcendental beauty of rasa will certainly be dragged down into material attraction, thus to act in material contamination and progress to the darkest region of hellish life. But by understanding :

1. the conjugal love of Rādhā and Kṛṣṇa one is freed from the grip of attraction to material so-called love between man and woman.
2. Similarly, one who understands the pure parental love of Nanda and Yaśodā for Kṛṣṇa will be saved from being dragged into material parental affection.
3.  If one accepts Kṛṣṇa as the supreme friend, the attraction of material friendship will be finished for him, and he will not be dismayed by so-called friendship with mundane wranglers. 
4. If he is attracted by servitorship to Kṛṣṇa, he will no longer have to serve the material body in the degraded status of material existence, with the false hope of becoming master in the future. 
5. Similarly, one who sees the greatness of Kṛṣṇa in neutrality will certainly never again seek the so-called relief of impersonalist or voidist philosophy. 

If one is not attracted by the transcendental nature of Kṛṣṇa, one is sure to be attracted to material enjoyment, thus to become implicated in the clinging network of virtuous and sinful activities and to continue material existence by transmigrating from one material body to another. Only in Kṛṣṇa consciousness can one achieve the highest perfection of life.

Relationship with Siksa Gurus and Diksha Guru- From CC Adi Chapter 1

Various points from srila Prabhupada's purports to the verses form the first chapter:

CC Adi 1.35

1. The secret is that one must submissively listen to those who know perfectly the science of God, and one must begin the mode of service regulated by the preceptor. 
2. A devotee already attracted by the name, form, qualities, etc., of the Supreme Lord may be directed to his specific manner of devotional service; he need not waste time in approaching the Lord through logic.
3.  The expert spiritual master knows well how to engage his disciple’s energy in the transcendental loving service of the Lord, and thus he engages a devotee in a specific devotional service according to his special tendency. 
4. A devotee must have only one initiating spiritual master because in the scriptures acceptance of more than one is always forbidden. There is no limit, however, to the number of instructing spiritual masters one may accept. 
5. One should always remember that a person who is reluctant to accept a spiritual master and be initiated is sure to be baffled in his endeavor to go back to Godhead.
6. The service of the spiritual master is essential. If there is no chance to serve the spiritual master directly, a devotee should serve him by remembering his instructions. There is no difference between the spiritual master’s instructions and the spiritual master himself. In his absence, therefore, his words of direction should be the pride of the disciple.
7. If one thinks that he is above consulting anyone else, including a spiritual master, he is at once an offender at the lotus feet of the Lord. Such an offender can never go back to Godhead. 
8. It is imperative that a serious person accept a bonafide spiritual master in terms of the śāstric injunctions. Śrī Jīva Gosvāmī advises that one not accept a spiritual master in terms of hereditary or customary social and ecclesiastical conventions. One should simply try to find a genuinely qualified spiritual master for actual advancement in spiritual understanding.

CC Adi 1.44:
Every living entity is essentially a servant of the Supreme Personality of Godhead, and the spiritual master is also His servant. Still, the spiritual master is a direct manifestation of the Lord. With this conviction, a disciple can advance in Kṛṣṇa consciousness. The spiritual master is nondifferent from Kṛṣṇa because he is a manifestation of Kṛṣṇa.
The spiritual master’s eternal occupation is to expand the service of the Lord by training disciples in a service attitude.

CC Adi 1.45:
The relationship of a disciple with his spiritual master is as good as his relationship with the Supreme Lord. A spiritual master always represents himself as the humblest servitor of the Personality of Godhead, but the disciple must look upon him as the manifested representation of Godhead.

The proper method of worshipping Lord Caitanya

CC Adi 1.34

vande gurūn īśa-bhaktān īśam īśāvatārakān
tat-prakāśāṁś ca tac-chaktīḥ kṛṣṇa-caitanya-saṁjñakam

I offer my respectful obeisances unto the spiritual masters, the devotees of the Lord, the Lord’s incarnations, His plenary portions, His energies and the primeval Lord Himself, Śrī Kṛṣṇa Caitanya.

Krsna Das Kaviraj Goswami begins his writing of the Sri Caitanya Caritamrita by offering obeisances to the six principles of the absolute Truth.

1. Gurun:
1. Gurūn is plural in number because anyone who gives spiritual instructions based on the revealed scriptures is accepted as a spiritual master. Although others give help in showing the way to beginners, the guru who first initiates one with the mahā-mantra is to be known as the initiator, and the saints who give instructions for progressive advancement in Kṛṣṇa consciousness are called instructing spiritual masters. The initiating and instructing spiritual masters are equal and identical manifestations of Kṛṣṇa, although they have different dealings. Their function is to guide the conditioned souls back home, back to Godhead. Therefore Kṛṣṇadāsa Kavirāja Gosvāmī accepted Nityānanda Prabhu and the six Gosvāmīs in the category of guru.
2. Isa Bhaktan
1. refers to the devotees of the Lord like Śrī Śrīvāsa and all other such followers, who are the energy of the Lord and are qualitatively nondifferent from Him 
2. CC Adi 1.38:"There are innumerable devotees of the Lord, of whom Śrīvāsa Ṭhākura is the foremost. I offer my respectful obeisances thousands of times unto their lotus feet. "
3. CC Adi 1.43 Purport:There are many unalloyed devotees of the Supreme Personality of Godhead, all of whom are considered associates surrounding the Lord. Kṛṣṇa should be worshiped with His devotees. 
3. Isavatarakan
1. refers to ācāryas like Advaita Prabhu, who is an avatāra of the Lord. 
4. Tat- Prakasams
1. indicates the direct manifestation of the Supreme Personality of Godhead, Nityānanda Prabhu, and the initiating spiritual master.
5. Tac- chaktih
1. refers to the spiritual energies (śaktis) of Śrī Caitanya Mahāprabhu. Gadādhara, Dāmodara and Jagadānanda belong to this category of internal energy.

The six principles are differently manifested but all equally worship-able. Kṛṣṇadāsa Kavirāja begins by offering his obeisances unto them to teach us the method of worshiping Lord Caitanya. 
CC Adi 1.43 Purport: The diverse principles are therefore the eternal paraphernalia through which the Absolute Truth can be approached.