"A person who is very faithfully engaged in the worship of the Deity in the temple but does not know how to behave toward devotees or people in general is called a prākṛta-bhakta, or kaniṣṭha-adhikārī." Therefore, in the temple there must be the Deity of the Lord, and the Lord should be worshiped by the devotees. This combination of the devotees and the Deity creates a first-class transcendental place.
Aside from this, if a gṛhastha devotee worships the śālagrāma-śilā, or the form of the Deity at home, his home also becomes a very great place. It was therefore customary for members of the three higher classes—namely the brāhmaṇas, kṣatriyas and vaiśyas—to worship the śālagrāma-śilā, or a small Deity of Rādhā-Kṛṣṇa or Sītā-Rāma in each and every home. This made everything auspicious. But now they have given up the Deity worship. Men have become modernized and are consequently indulging in all sorts of sinful activities, and therefore they are extremely unhappy.
(Srimad Bhagavatam-----7:14:29-----purport).

Similarly, one who worships the śālagrāma-śilā can also be relieved of offenses. In the Brahmaṇḍa Purāṇa it is said that one who worships Lord Viṣṇu, whose four hands bear a conchshell, disc, lotus flower and club, can be relieved from the above offenses. In the Ādi-varāha Purāṇa it is said that a worshiper who has committed offenses may fast for one day at the holy place known as Śaukarava and then bathe in the Ganges.
(Srimad Bhagavatam-----7:5:23-24-----purport).

Especially in every brāhmaṇa's house there must be a śālagrāma-śilā to be worshiped by the brāhmaṇa family. This system is still current. People who are brāhmaṇas by caste, who are born in a brāhmaṇa family, must worship the śālagrāma-śilā. Unfortunately, with the progress of Kali-yuga, the so-called brāhmaṇas, although very proud of taking birth in brāhmaṇa families, no longer worship the śālagrāma-śilā. But actually it has been a custom since time immemorial that a person born in a brāhmaṇa family must worship theśālagrāma-śilā in all circumstances. In our Kṛṣṇa consciousness society, some of the members are very anxious to introduce worship of the śālagrāma-śilā, but we have purposely refrained from introducing it because most of the members of the Kṛṣṇa consciousness movement do not originally come from families of the brāhmaṇa caste. After some time, when we find that they are actually situated strictly in the line of brahminical behavior, śālagrāma-śilā worship will be introduced.
(Sri Caitanya Caritamrta-----1:13:86-----purport).

When the form of the Lord is carved from wood, stone or any other element, it is to be understood that the Supreme Personality of Godhead is there. Even logically we can understand that all material elements are expansions of the energy of the Lord. Since the energy of the Supreme Personality of Godhead is nondifferent from His personal body, the Lord is always present in His energy, and He manifests Himself on account of the ardent desire of a devotee. Since the Lord is supremely powerful, it is logical that He can manifest Himself in His energy. Deity worship or worship of the śālagrāma-śilā is not idol worship. The Deity of the Lord in the house of a pure devotee can act exactly as He can in His original transcendental personality.
(Sri Caitanya Caritamrta-----1:14:9-----purport).

Among the followers of the Vedic way, the śālagrāma-śilā, the vigraha of Nārāyaṇa, is worshiped in the form of a stone ball. In India, every brāhmaṇa still worships the śālagrāma-śilā in his home. The vaiśyas and kṣatriyas may also engage in this worship, but it is compulsory in the house of a brāhmaṇa.
(Sri Caitanya Caritamrta-----2:15:204-----purport).

The śālagrāma-śilā should be worshiped with tulasī where a sufficient quantity of tulasī leaves are available. Worship of śālagrāma-śilā should be introduced in all ISKCON temples. Śālagrāma-śilā is the form of the Lord's mercy. To worship the Deity with the sixty-four items mentioned may be a difficult job, but the Lord has become so small that anyone in any temple can carefully handle Deity worship simply by performing the same activities with the śālagrāma-śilā.
(Sri Caitanya Caritamrta-----2:24:336-----purport).

Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura adds in his Anubhāṣya: "In the Bengali year 1283 (A.D. 1876) a bābājī of the name Nitāi dāsa arranged for a donation of twelve bighās of land (about four acres) for the temple where Uddhāraṇa Datta Ṭhākura worshiped. The management of the temple later deteriorated, but then in 1306 (A.D. 1899), through the cooperation of the famous Balarāma Mullik of Hugli, who was a subjudge, and many rich suvarṇa-vaṇik community members, the management of the temple improved greatly. Not more than fifty years ago, one of the family members of Uddhāraṇa Datta Ṭhākura named Jagamohana Datta established a wooden mūrti (statue) of Uddhāraṇa Datta Ṭhākura in the temple, but that mūrti is no longer there; at present, a picture of Uddhāraṇa Datta Ṭhākura is worshiped. It is understood, however, that the wooden mūrti of Uddhāraṇa Ṭhākura was taken away by Śrī Madana-mohana Datta and is now being worshiped with a śālagrāma-śilā by Śrīnātha Datta."
(Sri Caitanya Caritamrta-----1:11:41-----purport).

"In the family of Puruṣottama Cakravartī there are famous persons like Kuñjavihārī Cakravartī and Rādhāvallabha Cakravartī, who now live in the district of Birbhum. They professionally recite songs from Caitanya-maṅgala. It is said that when Maṅgala Ṭhākura was constructing a road from Bengal to Jagannātha Purī, he found a Deity of Rādhāvallabha while digging a lake. At that time he was living in the locality of Kāṅdaḍā, in the village named Rāṇīpura. The śālagrāma-śilā personally worshiped by Maṅgala Ṭhākura still exists in the village of Kāṅdaḍā. A temple has been constructed there for the worship of Vṛndāvana-candra. Maṅgala Ṭhākura had three sons—Rādhikāprasāda, Gopīramaṇa and Śyāmakiśora. The descendants of these three sons are still living."
(Sri Caitanya Caritamrta-----1:12:87-----purport).

In the days of Haridāsa Ṭhākura, all the brāhmaṇas worshiped Nārāyaṇa in the form of the śālagrāma-śilā. Therefore begging from a brāhmaṇa's house meant taking kṛṣṇa-prasādam, which is transcendental (nirguṇa). If we take food from the houses of others, such as karmīs, we shall have to share the qualities of those from whom we take alms. Therefore Śrī Caitanya Mahāprabhu took prasādam in the houses of Vaiṣṇavas. This is the general process.
(Sri Caitanya Caritamrta-----3:3:101-----purport).

So everyone can bhakti-yoga practice, simply under the guidance of proper spiritual master who knows the science of Kṛṣṇa. From him you take lesson. And it is not difficult, this bhakti-yoga practice. Actually, this was the practice in India in every home. There was Deity. At least, brāhmaṇa, kṣatriya, vaiśya, they had Deity, Rādhā-Kṛṣṇa, Sītā-Rāma, or Lakṣmī-Nārāyaṇa, or Nārāyaṇa śilā. Every house, it was being worshiped. But we have lost our culture. Vāsudeve bhakti-yogaḥ..., bhakti-prayojitaḥ. We have lost this culture. Revive it. Don't lose this opportunity of human life. Practice bhakti-yoga and be Kṛṣṇa conscious, and make your life successful.
(Lecture on Srimad Bhagavatam-----1:2:7).