Ms. Pokharel,
I presume you do not know the origin of this presentation. Could you please trace its origin please and let me know the authority on which this is based.
According to Thakur "Satchitnanda is the only Guru". He gave the mantra "Hari Guru, Guru Hari" to Nati Binodini. In other words Guru is Satcitananda in human form. Thakur says that eventually Guru makes the disciple see His ishta and merges in the same - becomes one with the Ishta.
In Mahabharata, Ekalavya took Dronacharaya as his Guru although Dronacharaya did not take him as disciple. Ekalavya perfected archery using a clay image of his Guru. Who taught him archery? Teacher or Guru or Satchitananda Himself through the clay image which only helped him to concentrate his mind? There was no human being even! Also Dronacharaya wronged him by asking for his thumb as Guru Dakhisna. So we see that even the character / quality of Guru is also not important for disciples achievement. Thakur used to say "even though my Guru visits the pub, He is still Nityananda Roy (meaning God)".
Thakur Himself had two Gurus, both of whom were imperfect but Thakur still achieved His goal.
Teacher is Guru.
Jai Thakur