eka krishna name kore sarva papa nasa
premera karana bhakti korena prakasa
premera udaye hoy premera vikara
sveda kampa pulakadi gadgadasru dhara
anayase bhava kshaya krishnera sevana
eka krishna namera phale pai eto dhana
heno krishna nama yadi loy bahubara
tabu yadi prema nahe, nahe asrudhara
tabe jani aparadha tahate pracura
krishna nama bija tahe na hoy ankura
(Caitanya Caritamrita, Adi-lila, chapter 8)

“One utterance of Krishna’s name destroys all sins and causes devotion and love of God to appear. When prema arises, the devotee shows all its symptoms, such as sweating, shivering, horripilating, a faltering voice and crying streams of tears. Liberation from the material world, which is attained by serving Krishna, is easily attained by simply once uttering the name of Krishna. When you chant this name of Krishna many times, but still you don’t feel love and there are no tears of love streaming from your eyes, then I know that there must be many offenses committed, so that the seed of Krishna’s name cannot sprout.”

One may ask here:
If the glories of the holy name are so unhindered, then why is there still consideration of offenses? If offenses dim the greatness of the name, then how can the holy name be called unrestricted?
The answer is that mist cannot cover the sun, it can only cover the sun from our eyes. Because mist may cover the sun, the sunrays cannot fall on us. Similarly, nothing can actually cover the self-manifest greatness of the holy name, but offenses cover our hearts in such a way that its powers cannot fall into our hearts. But when the mist dissolves, the sunrays can fall on us unhindered. Similarly, when offenses disappear, the strength of the holy name is freely experienced in the heart. It is just like a king, who is able at any time to make any poor man rich. But if the king is displeased with someone, and he does not want to give his wealth to him, it does not mean that he is not able to give that wealth! In the same way, the holy name is able to give prema to the offensive chanter, but he will not give it because he simply does not want to give it. That is why the practising devotee should chant the holy name without committing offenses. Even if one chants for a long time, prema will not come in the heart as long as one commits offenses. That is why the devotional scriptures are always warning the practising devotees to beware of offenses.
When we investigate the root cause of offenses, then we can see that it is an envious mood that stops love from entering our hearts. This envy finds its cause in false egotism, and as a result a low person may consider himself to be the greatest, the ignorant may think themselves to be very learned, and one is unable to see one’s own fault and another person’s qualities. Thus one praises oneself and criticises others. In this way offensive persons are envious of another person’s success and cannot tolerate the greatness of another Vaishnava, although he can clearly recognise that greatness. They may even consider the guru, who is the very form of God’s great mercy (karunya ghana vigraha) to be an ordinary human being and they cannot have faith in the glorification of the holy name, even if they have clearly heard it. False words, violent behaviour and sinful acts like theft and so will create great offenses in the heart of such an envious and deceitful person. In the Padma Purana ten offenses to the holy name are written down and we will briefly describe them below:

1) sadhu ninda (blaspheming the saint): Blaspheming the saint is a grave offense, and is called mahad aparadha. A sadhu is a devotee of God through whose preaching the holy name has become world famous. How can the holy name tolerate blasphemy of such a person? Many people think that there is no harm in discussing the fault of some devotee who is engaged in some wicked activities, because that criticism is true and justified, but Sripada Sridhara Svami writes in his commentary on Srimad Bhagavata: nindanam dosha kirtanam – “There is no question whether the devotee who is under discussion is at fault or not, speaking bad about such a person is called blasphemy.” It is natural that we wonder: “Who are these devotees, offending whom we commit an offense to the holy name?” In his book Madhurya Kadambini, Srila Visvanatha Cakravarti gives the answer: “It is not proper to think that only those devotees who are merciful, nonviolent, tolerant etc. are to be considered saints, and that those who are not endowed with such qualities are not saints, and that one can thus blaspheme them without committing an offense to the holy name. Actually, anyone who worships God, be he deceitful, ill-behaved, hypocritical and unclean, is a saint, and to blaspheme or criticise such a person is an offense to the holy name. Sri Krishna Himself says in Bhagavad Gita (9.30):

api cet suduracaro bhajate mam ananya bhak
sadhur eva sa mantavyah samyag vyavasito hi sah

“Even if one commits the most abominable activities, he is to be considered a saint when he exclusively worships Me, for he is on the right path.”

Those who have fixed the thought in their mind, “I will be blessed by worshipping the Supreme Lord”, and who do not worship demigods, but only the Supreme Lord, are saints, even if they misbehave, and to criticise even them is an offense to the holy name.

…

from “The Siksastakam” with commentaries by Srila Ananta das Babaji