Being a Spiritual Master or teacher (Guru) and a disciple, are very serious positions, both need full commitment and mature knowledge by always being genuinely Krsna conscious.

Srila Prabhupada - "You have asked if it is true that the Spiritual Master remains in the material universe until all of His disciples are transferred to the Spiritual Sky, the answer is yes, this is the rule. 

Therefore, every student should be very much careful not to commit any offence which will be detrimental to this promotion to the Spiritual Kingdom, and thereby the Spiritual Master has to incarnate again to deliver him. 

This sort of mentality will be a kind of offence to the Spiritual Master. Out of the ten kinds of offences, the number one offence is to disobey the orders of the Spiritual Master. 

The instructions given to the disciple by the Spiritual Master at the time of initiation should be strictly followed. That will make one advance to the spiritual path. 

But if one deliberately defies such instructions, then his advancement is hampered from the very beginning. This defying means to disconnect the relationship with the Spiritual Master. 

And anyone who defies and therefore disconnects the relationship with the Spiritual Master can hardly expect the assistance of the Spiritual Master life after life. 

I hope this will clear up this question sufficiently for you."  (Letter to Jayapataka, Los Angeles, 11 July,1969)

Devotee - "Prabhupāda, I heard it said that the spiritual master will always come back until his devotees, his disciples, have achieved God realization. Can you explain that?"

Srila Prabhupāda - "Yes, but don't try to take advantage of it. (laughter) Don't try to give trouble to your spiritual master like that. Finish your business in this life. That is especially meant for those who are slack. His devotee, his disciple should be serious in serving spiritual master. If he is intelligent he should know that- 

"Why should I act in such a way that my spiritual master has to take the trouble to reclaim me again? Let my business be finished in this life." 

That should be the right way of thinking. Not that, "Oh I am sure my spiritual master will come, let me do all nonsense." No. So if you have got any, I mean to say, affection for the spiritual master, then you should finish your business in this life so that he may not come again to reclaim you. Is that all right? 

Don't take advantage of this business. Rather, be serious to finish your business. That is a fact.

There is an instance of Bilvamaṅgala Ṭhākura.

 Bilvamaṅgala Ṭhākura was in his previous life, elevated to almost prema-bhakti, highest platform of devotional service. But there is always chance of falldown. 

So somehow or other he fell down. And next life he was born in a very rich family as it is stated in the Bhagavad-gītā: śucīnāṁ śrīmatāṁ gehe (BG 6.41). 

So he was born in a rich brāhmaṇa family, but he became, naturally as rich boys become attached to woman-hunter. 

So it is said that his spiritual master instructed him through his prostitute. At the right moment, his spiritual master said through that prostitute, 

"Oh, you are so much attached with this flesh and bone. If you had been attached so much with Kṛṣṇa, how good you could have achieved." 

Immediately he took to that position. So that responsibility is for the spiritual master. But we should not take advantage of that. That is not very good. We should understand-

yasya prasādād bhagavat prasādo.

yasyāprasādān na gatiḥ kuto pi.

dhyāyan stuvaṁs tasya yaśas tri-sandhyaṁ

vande guroḥ śrī-caraṇāravindam"

This means-

"By satisfaction of the spiritual master, the Supreme Personality of Godhead becomes satisfied. And by not satisfying the spiritual master, there is no chance of being promoted to the plane of Kṛṣṇa consciousness. I should, therefore, meditate and pray for his mercy three times a day, and offer my respectful obeisances unto him, my spiritual master.

We should not try to put our spiritual master in a position that he has to reclaim me from prostitute's house. But he has to do it. Because he accepts his disciple, he has got the responsibility like that." (Lecture on BG 6.46-47,Los Angeles, February 21, 1969)