Arjuna worshipped Drona, the alive human form directly. Ekalavya worshipped the statue of Drona as the representative model. Of course, both learnt the worldly branch of education related to war (Pravrutti). Here, there is no context of spiritual knowledge (Nivrutti). Even then, we can learn that Arjuna through direct worship (Saakshaat Upaasanam) succeeded than Ekalavya, who worshipped through model-representation (Pratika Upaasanam). Later on, Arjuna has to fight against Drona and Ekalavya fought on the side of Drona. Here Arjuna came on the side of Lord Krishna and hence, he shifted from the direct worship of the preacher (Guru) to the direct worship of God-cum-Preacher (Satguru). This difference made Arjuna to succeed and Ekalavya to get defeated. All this is the field of worldly affairs (Pravrutti) only and it can be concluded that in Pravrutti and Nivrutti:
1) The direct worship is better than the indirect worship and
2) The God-cum-Preacher is far superior to an ordinary Preacher.
Arjuna did not completely surrender to Lord Krishna in Pravrutti or Nivrutti. He followed the order of Krishna in the Kurukshethra war, whereas Arjuna fought against Krishna in protecting Gaya. Even in Nivrutti, Arjuna showed this mixed behavior. He showed his ignorance about Krishna as God while questioning Krishna about His preaching to the Sun in the beginning of the creation. At the same time, he praised Lord Krishna as God during the context of cosmic vision. He worshipped the representative model of Lord Shiva (Shivalingam) for the sake of victory in the war while the same God exists before him in alive human form as Krishna. At the same time, he surrendered to Krishna treating Him as God at the end of the preaching of the Gita. This mixed behavior of Arjuna represents the partial knowledge and partial ignorance of human being. The human beings sometimes recognize the contemporary human incarnation and totally surrender. But, sometimes, they neglect the same human incarnation due to ego and jealousy especially in the case of constant association. Ravana was a devil and never recognized Rama, the contemporary human incarnation. He worshipped Lord Shiva through indirect worship but neglected the same Lord on seeing directly by showing desire towards the wife of the Lord. Ekalavya also did not recognize Krishna as the contemporary human incarnation and fought against Him. Both Ravana and Ekalavya were always indulged in the indirect worship only, since ego and jealousy predominate quickly in the case of direct worship as hurdles. If you see the case of angels having full knowledge, Ramanuja and Madhva never showed any negligence to their preachers or even to the devotees. Hanuman and Radha worshipped their contemporary human incarnations only.
The Gita also classified these three categories as ‘Ishtam’ representing angels, ‘Mishram’ representing the human beings and ‘Anishtam’ representing the demons. It is also said in the Gita that angels are elevated to the upper plane, the human beings stand in the middle plane and the demons fall to the lower planes. The angels and demons are present in the human beings only. The human beings having predomination of Sattvam are angels and the human beings having predomination of Tamas are demons. The angels never err. The human beings err but realize and rectify. The demons always err and never realize due to ego. The animals also err but are incapable of realization. Therefore, God excuses the realized human beings and the animals, which can never realize. But, God will never excuse the demons, who are capable of realization, but never realize due to ego.