"The religion of the Veda knows no idols, then why worship such things as god, which are non -Vedic and enter in to darkness [ignorance].

The belief system preaches that God is one and the ways to God are many. It simply tries to lead them to darkness with its dogma and the  idea of many gods, which is apart from the self.

The eternal truth within the universe[mind] and it is without the universe[mind]. Direct knowledge of Self can be acquired by one through the Self while realizing the Self. Self- realization is the essence of human existence. Where there is unity, one without a second; there is world of non-dual reality. The non-dual truth is ultimate truth. And ultimate truth itself is God.

"The religion of the Veda knows no idols, then  why worship such things as god, which are non-Vedic and enter  in to darkness (ignorance).   

"Andhatama pravishanti ye asambhuti mupaste". [Yajurved 40:9]

Translation 1.
They enter darkness, those who worship natural things (for example air, water, sun, moon, animals, fire, stone, etc).
They sink deeper in darkness those who worship sambhuti. (Sambhuti means created things, for example table, chair, idol etc.)
[Yajurved 40:9]

Translation 2.
"Deep into shade of blinding gloom fall asambhuti's worshippers. They sink to darkness deeper yet who on sambhuti are intent."
[Yajurveda Samhita by Ralph T. H. Giffith pg 538]

Translation 3.
"They are enveloped in darkness, in other words, are steeped in ignorance and sunk in the greatest depths of misery who worship the uncreated, eternal prakrti -- the material cause of the world -- in place of the All-pervading God, But those who worship visible things born of the prakrti, such as the earth, trees, bodies (human and the like) in place of God are enveloped in still greater darkness, in other words, they are extremely foolish, fall into an awful hell of pain and sorrow, and suffer terribly for a long time."
[Yajur Veda 40:9.]

"Na tasya pratima asti"
"There is no image of Him."[Yajurveda 32:3]

"Ekam evadvitiyam"
"He is One only without a second." [Chandogya Upanishad 6:2]

"Na casya kascij janita na cadhipah."
"Of Him there are neither parents nor lord." [Svetasvatara Upanishad 6:9]

"Na tasya pratima asti"
"There is no likeness of Him." [Svetasvatara Upanishad 4:19]

"shudhama poapvidham"
"He is bodiless and pure." [Yajurveda 40:8]

"Na samdrse tisthati rupam asya, na caksusa pasyati kas canainam."

"His form is not to be seen; no one sees Him with the eye." [Svetasvatara Upanishad 4:20]

The religion of the Veda knows no idols:-

"The religion of the Veda knows no idols," says Max Müller; "the worship of idols in India is a secondary formation, a degradation of the more primitive worship of ideal gods."

Self- knowledge is the highest knowledge. Self is closer to man than his own veins." "With the knowledge of the self, man will begin to know the self is not physical but self is formless consciousness, so as to finally achieve the self-awareness." "With the perfect understanding of the true self, man becomes conscious that self is the consciousness. For Advitin- the self alone is the God or Lord because:-

 Mysticism gives only temporary peace within the illusion, because it is based on the mystical experience experienced in the unreal world. Only self-knowledge can yield permanent peace.

Krishna is teaching no particular religion, but Religion in general. The Gita nowhere refers to Hindu, Vaishnava or Saiva Matam or Dharma. The entire civilized world's need is now, to lift its viewpoint from particular religions to universal truth.

In Vedas the God has been described as:-

v  Sakshi (Witness)

v  Chetan (conscious)

v  Nirguna (Without form and properties).

v  Nitya (eternal)

v  Shuddha (pure)

v  Buddha (omniscient)

v   Mukta (unattached).

It indicates clearly all the gods with form and attributes are mere imagination based on the false self.  The true god is self, which Atman.  Therefore Self-Realization is god realization.

As indicated in ISH Upanishads: - By worshiping gods and goddesses you will go after death to the world of gods and goddesses. But will that help you? The time you spend there is wasted, because if you were not there you could have spent that time moving forward towards Self-knowledge, which is your goal. In the world of gods and goddesses you cannot do that, and thus you go deeper and deeper into darkness.

It clearly indicates that:-If the human goal is to acquire Self-Knowledge then why one has to indulge in rituals and glorifying the conceptual gods, goddesses and gurus to go in to deeper darkness. Instead   spend that time moving forward towards Self-knowledge, which is one’s prime goal.   

Since it is eternal and infinite, it comprises the only truth. The goal of Vedic religion, through the various yogas, is to realize that the consciousness (Atman) is actually nothing but Brahman.

Brahman means universal truth. Brahman is considered the all-pervading consciousness, which is the basis of all the animate and inanimate entities and material. (brahmano hi pratisthaham, Bhagavad Gita 14.27)

Sri, Sankara’s notion of Maya, the cosmic illusion, which must be transcended in order to realize the truth of Brahman, which means ultimate truth.   

If Brahman is considered the all-pervading consciousness then, it is necessary to realize, the consciousness as self, which pervades all the three states, to realize the fact that, there is no second thing exists other the consciousness. Thus, consciousness (Atman) is ultimate truth  or Brahman.   Brahman is ultimate truth and ultimate truth is God. thus holding anything other than Brahman as god is erroneous.  thus self-realization is God realization because the formless soul or consciousness , the innermost self itself is god.

 

When Yajur Veda clearly declares worshiping human bodies in place of the god ,which is the self are enveloped in greater darkness then why glorify the guru[body] and fall in the darkness.

The worship or glorifying gurus does not free one from ignorance

"They are enveloped in darkness, in other words, are steeped in ignorance and sunk in the greatest depths of misery who worship the uncreated, eternal prakrti -- the material cause of the world -- in place of the All-pervading God, But those who worship visible things born of the prakrti, such as the earth, trees, bodies (human and the like) in place of God are enveloped in still greater darkness, in other words, they are extremely foolish, fall into an awful hell of pain and sorrow, and suffer terribly for a long time." [Yajur Veda 40:9.]

Those who worship visible things born of the prakrti, such as the earth, trees, bodies (human and the like) in place of God are enveloped in still greater darkness-- 

When Yajur Veda clearly declares worshiping human bodies  in place of the god ,which is the self are enveloped in greater darkness then why glorify the guru[body]  and  fall in the darkness. 

In olden days men were primitive in their thought, so that a man having little knowledge was considered a genius. Now-a-days our knowledge is so advanced that the genius of those days would be an ordinary man of today. Therefore if one finds truth, free his -self from the tyranny of environment and tradition, not by condemning them but by examining and testing them by deeper inquiry, analysis and reasoning to find out  whether they be true or not. Accept nothing on the authority of a god men or genius of the past or present but only if it prove true after examination.

The people with the same  mindsets  is always willing to examine facts and judge them calmly whereas the religious scholars and intellectuals  will be immune to all facts and hold hard to their delusions. Such people do not want truth but only what pleases them. This is because the ego in them is so strong.  Their attitude is “What pleases them is truth, what they dislike is false. 

The worship or glorifying gurus does not free one from ignorance. The rewards are none to them, the reward achieved in their lives are of consequence and not the result of worshiping and glorifying the gurus.

People always need some sort of hope when their minds are not yet enlightened. "Self is closer to man than his own veins." "With the Self- Knowledge or Brahma Gnana or Atma Gnana, one will begin to know the ultimate truth, so as to finally realize the fact that, self is not physical and becomes conscious that the true self is the Spirit."

Most people lack the patience and perseverance in investigating and collecting all the data  before judging: hence they assume guru are god men  are great because other people  say so, or that he is wise because he himself says so, or that what he teaches is true because it attracts them. Such an   attitude and easy assumptions becomes obstacle to fold the truth and it requires some trouble to put into effect.