For those who are very materialistic and cannot understand the situation of the spiritual world, the abode of Kṛṣṇa, great sages have recommended the yogic process whereby one gradually rises from meditation on the abdomen, which is called mūlādhāra or maṇipūraka meditation. Mūlādhāra and maṇipūraka are technical terms which refer to the intestines within the abdomen. Grossly materialistic persons think that economic development is of foremost importance because they are under the impression that a living entity exists only by eating. Such grossly materialistic persons forget that although we may eat as much as we like, if the food is not digested it produces the troubles of indigestion and acidity. Therefore, eating is not in itself the cause of the vital energy of life. For digestion of eatables we have to take shelter of another, superior energy, which is mentioned in the Bhagavad-gītā as vaiśvānara. Lord Kṛṣṇa says in the Bhagavad-gītā that He helps the digestion in the form of vaiśvānara. The Supreme Personality of Godhead is all-pervasive; therefore, His presence in the stomach as vaiśvānara is not extraordinary.
Kṛṣṇa is actually present everywhere. The Vaiṣṇava, therefore, marks his body with temples of Viṣṇu: he first marks a tilaka temple on the abdomen, then on the chest, then between the collarbones, then on the forehead, and gradually he marks the top of the head, the brahma-randhra. The thirteen temples of tilaka marked on the body of a Vaiṣṇava are known as follows: On the forehead is the temple of Lord Keśava, on the belly is the temple of Lord Nārāyaṇa, on the chest is the temple of Lord Mādhava, and on the throat, between the two collarbones, is the temple of Lord Govinda. On the right side of the waist is the temple of Lord Viṣṇu, on the right arm the temple of Lord Madhusūdana, and on the right side of the collarbone the temple of Lord Trivikrama. Similarly, on the left side of the waist is the temple of Lord Vāmanadeva, on the left arm the temple of Śrīdhara, on the left side of the collarbone the temple of Hṛṣīkeśa, on the upper back the temple called Padmanābha, and on the lower back the temple called Dāmodara. On the top of the head is the temple called Vāsudeva. This is the process of meditation on the Lord's situation in the different parts of the body, but for those who are not Vaiṣṇavas, great sages recommend meditation on the bodily concept of life—meditation on the intestines, on the heart, on the throat, on the eyebrows, on the forehead and then on the top of the head. Some of the sages in the disciplic succession from the great saint Aruṇa meditate on the heart, because the Supersoul stays within the heart along with the living entity. This is confirmed in the Bhagavad-gītā, Fifteenth Chapter, wherein the Lord states, “I am situated in everyone's heart.”
As part of devotional service, Vaiṣṇavas protect the body for the service of the Lord, but those who are gross materialists accept the body as the self. They worship the body by the yogic process of meditation on the different bodily parts, such as maṇipūraka, dahara and hṛdaya, gradually rising to the brahma-randhra, on the top of the head. The first-class yogī who has attained perfection in the practice of the yoga system ultimately passes through the brahma-randhra to any one of the planets in either the material or spiritual worlds. How a yogī can transfer himself to another planet is vividly described in the Second Canto of Śrīmad-Bhāgavatam.
In this regard, Śukadeva Gosvāmī has recommended that the beginners worship the virāṭ-puruṣa, the gigantic universal form of the Lord. One who cannot believe that the Lord can be worshiped with equal success in the Deity, or arcā form, or who cannot concentrate on this form is advised to worship the universal form of the Lord. The lower part of the universe is considered the feet and legs of the Lord's universal form, the middle part of the universe is considered the navel or abdomen of the Lord, the upper planetary systems such as Janaloka and Maharloka are the heart of the Lord, and the topmost planetary system, Brahmaloka, is considered the top of the Lord's head. There are different processes recommended by great sages according to the position of the worshiper, but the ultimate aim of all meditational yogic processes is to go back home, back to Godhead. As stated in the Bhagavad-gītā, anyone who reaches the highest planet, the abode of Kṛṣṇa, or even the Vaikuṇṭha planets, never has to come down again to this miserable material condition of life.