SB Canto 4

Bhaktivinoda Ṭhākura offers to become a Vaiṣṇava's dog. A dog always keeps himself at his master's door and does not allow any person unfavorable to the master to enter. Similarly, one should engage in the service of a Vaiṣṇava and try to please him in every respect.

SB 4.29.30-31, Purport: 

The living entity's position is herein likened to a dog's. By chance a dog may have a very rich owner, and by chance he may become a street dog. As the dog of a rich man, he will live very opulently. Sometimes in Western countries we hear of a master leaving millions of dollars to a dog in his will. Of course, there are many dogs loitering in the street without food. Therefore, to liken the conditional existence of the living entity to that of a dog is very appropriate. An intelligent human being, however, can understand that if he has to live the life of a dog, he had best become Kṛṣṇa's dog. In the material world a dog is sometimes elevated and is sometimes on the street, but in the spiritual world, Kṛṣṇa's dog is perpetually, eternally happy. ŚrīlaBhaktivinoda Ṭhākura has therefore sung: vaiṣṇava ṭhākura tomāra kukura baliyā jānaha more. In this wayBhaktivinoda Ṭhākura offers to become a Vaiṣṇava's dog. A dog always keeps himself at his master's door and does not allow any person unfavorable to the master to enter. Similarly, one should engage in the service of a Vaiṣṇava and try to please him in every respect. Unless one does so, he does not make spiritual advancement.

SB Canto 7

(Kadamba Kanana Swami, 20 March 2013, Cape Town, South Africa, Srimad Bhagavatam 8.12.6)

Pure devotees of the Lord are only interested in satisfying the senses of the Supreme Lord,hṛṣīkeṇa hṛṣīkeśa-sevanaṁ bhaktir ucyate(Bhakti-rasamrta-sindhu 1.1.2). They are not concerned with the material world because they appreciate that in the material world, everything is only temporary and therefore any relationship that we have with the material energy, will not endure and therefore it will be painful.

Whatever we have, we become attached to and then it will disintegrate in the course of time. That's the nature of anything material, so what is the point? "I love my beautiful sandcastle; it is so wonderful. But it will not last; it will be destroyed; so many dreams."

But the love for these dreams comes from the heart because there is a natural need within the living being for happiness and fulfillment. In this material world, we are always experiencing some emptiness within the heart, always experiencing some yearning, some longing for something, some hope that maybe it will happen. Whatever it is, whatever we want, "Maybe I'll become rich… maybe I'll become famous… or rich and famous! Maybe one day I'll wake up and I'll be beautiful… it's doubtful but maybe somehow or other, a miracle will happen, you never know! It could happen, therefore, just wait, just in case. Hold onto to that little straw because maybe it will happen and I so much want it to happen. Oh yes, maybe my love will appear. Yes, the one that is my perfect match, the one that is designed for me, that one!'

Of course, that one doesn't exist; there is no perfect match, it doesn't exist! It becomes a boxing match sooner or later. It's not a perfect match, it is not like that. It's hard work to make relationships work. You cannot say that there is a marriage that just works. No, you have to work for it. It's hard for relationships to work and then still you don't really get what you were dreaming of. That's the material world!

Anyway some say, "Yes, but better a blind uncle than none. Better something than nothing at all!"Okay yes, we want something after all. Alright have it, if you want to settle for something but let that something that you want out of the material world not interfere with your eternal progress! So it cannot be sinful because when we fulfill our desires in a sinful way, then we become bound up by the laws of material nature.

na te viduḥ svārtha-gatiṁ hi viṣṇuṁ
durāśayā ye bahir-artha-māninaḥ
andhā yathāndhair upanīyamānās
te 'pīśa-tantryām uru-dāmni baddhāḥ, (SB 7.5.31)

"Come one, don't be a square! Yeah, it's okay, everybody's doing it, everybody."

Andhā yathāndhair upanīyamānās, and the blind are leading the blind. Te 'pīśa-tantryām uru-dāmni baddhāḥ, and the result is that we remain bound up in chains. The whole world is doing it and they all just remain bound up in chains, in this material world. The three gunas, sometimes known as the three qualities of material nature, other times known as the three ropes that bind us; that is what will happen.

So the pure devotee doesn't even bother with such things. The pure devotee is thinking about Krsna. Krsna is important, Krsna's desires are important, Krsna's glory is important, Krsna's service is important, Krsna's name is important, tadīyānāṁ samarcanam (CC Madhya-lila 11.31); anything related to Krsna is important. Tadīyā, anything related to Krsna. The Ganga because of the dust of Krsna's lotus feet. Tulasi Devi is related to Krsna, 'tulasī kṛṣṇa-preyasi,' anything related to Krsna.

'ārādhanānāṁ sarveṣāṁ
viṣṇor ārādhanaṁ param
tasmāt parataraṁ devi
tadīyānāṁ samarcanam,' (Padma Purana, quoted in CC Madhya-lila 11.31).

Lord Siva said to Parvarti in the Padma Purana, "Of all that are worshipable, the Supreme Lord Visnu is the ultimate worshipable entity. But greater still are those personalities and things that are related to him in service.' That is wonderful!