As confirmed in Bhagavad-gita (18.61), the Supreme Personality of Godhead Sri Krsna is the all-pervading omnipresent Supersoul. Therefore one who is a yogi can worship only Him because He is the substance and not illusion
SB Canto 2
Thus being fixed, one must render service unto the Supersoul situated in one's own heart by His omnipotency. Because He is the Almighty Personality of Godhead, eternal and unlimited, He is the ultimate goal of life, and by worshiping Him one can end the cause of the conditioned state of existence.
As confirmed in Bhagavad-gita (18.61), the Supreme Personality of Godhead Sri Krsna is the all-pervading omnipresent Supersoul. Therefore one who is a yogi can worship only Him because He is the substance and not illusion. Every living creature is engaging in the service of something else. A living being's constitutional position is to render service, but in the atmosphere of maya, or illusion, or the conditional state of existence, the conditioned soul seeks the service of illusion. A conditioned soul works in the service of his temporary body, bodily relatives like the wife and children, and the necessary paraphernalia for maintaining the body and bodily relations, such as the house, land, wealth, society and country, but he does not know that all such renderings of service are totally illusory. As we have discussed many times before, this material world is itself an illusion, like a mirage in the desert. In the desert there is an illusion of water, and the foolish animals become entrapped by such an illusion and run after water in the desert, although there is no water at all. But because there is no water in the desert, one does not conclude that there is no water at all. The intelligent person knows well that there is certainly water, water in the seas and oceans, but such vast reservoirs of water are far, far away from the desert. One should therefore search for water in the vicinity of seas and oceans and not in the desert. Every one of us is searching after real happiness in life, namely eternal life, eternal or unlimited knowledge and unending blissful life. But foolish people who have no knowledge of the substance search after the reality of life in the illusion. This material body does not endure eternally, and everything in relation with this temporary body, such as the wife, children, society and country, also changes along with the change of body. This is called samsara, or repetition of birth, death, old age and disease. We would like to find a solution for all these problems of life, but we do not know the way. Herein it is suggested that anyone who wants to make an end to these miseries of life, namely repetition of birth, death, disease, and old age, must take to this process of worshiping the Supreme Lord and not others, as it is also ultimately suggested in the Bhagavad-gita (18.65). If we at all want to end the cause of our conditioned life, we must take to the worship of Lord Sri Krsna, who is present in everyone's heart by His natural affection for all living beings, who are actually the parts and parcels of the Lord (BG 18.61). The baby in the lap of his mother is naturally attached to the mother, and the mother is attached to the child. But when the child grows up and becomes overwhelmed by circumstances, he gradually becomes detached from the mother, although the mother always expects some sort of service from the grown-up child and is equally affectionate toward her child, even though the child is forgetful. Similarly, because we are all part and parcel of the Lord, the Lord is always affectionate to us, and He always tries to get us back home, back to Godhead. But we, the conditioned souls, do not care for Him and run instead after the illusory bodily connections. We must therefore extricate ourselves from all illusory connections of the world and seek reunion with the Lord, trying to render service unto Him because He is the ultimate truth. Actually we are hankering after Him as the child seeks the mother. And to search out the Supreme Personality of Godhead, we need not go anywhere else, because the Lord is within our hearts. This does not suggest, however, that we should not go to the places of worship, namely the temples, churches and mosques. Such holy places of worship are also occupied by the Lord because the Lord is omnipresent. For the common man these holy places are centers of learning about the science of God. When the temples are devoid of activities, the people in general become uninterested in such places, and consequently the mass of people gradually become godless, and a godless civilization is the result. Such a hellish civilization artificially increases the conditions of life, and existence becomes intolerable for everyone. The foolish leaders of a godless civilization try to devise various plans to bring about peace and prosperity in the godless world under a patent trademark of materialism, and because such attempts are illusory only, the people elect incompetent, blind leaders, one after another, who are incapable of offering solutions. If we want at all to end this anomaly of a godless civilization, we must follow the principles of revealed scriptures like the Srimad-Bhagavatam and follow the instruction of a person like Sri Sukadeva Gosvami who has no attraction for material gain.