When we seek Lord Narayana, our sins are destroyed, just as thorns are burnt by a fire. But our karmas keep us from the right path.
Even punyas, that is the result of our good deeds, keep us chained to samsara.
Think of a person in a dungeon. Is his lot any better if he is tied up using chains made of gold? A chain is a chain, whether it is made of a cheap material or gold. Punyas, without bhakti or surrender, will also keep us from moksha, said Adur Asuri Madhavachari. The punyas are akin to chains of gold.
In the absence of bhakti or surrender, our good deeds will not result in moksha. They may lead us to swarga, but not to moksha.
When the effect of our good deeds is used up, we have to leave swarga and be reborn on this earth, and so the cycle of births and deaths continues. None of this means that we should not resort to good deeds. What this means is that we must understand the true paths to liberation, namely bhakti or surrender.
Our good deeds will cleanse our hearts and prepare us for bhakti or surrender, and through bhakti or surrender, we will get liberation from births and deaths.
In the case of a person who has resorted to total surrender, liberation occurs the moment the mortal coils are cast away.
In the case of the one who has resorted to the path of bhakti, the release from the cycle of births and deaths, will be whenever the consequences of his karma end.
When a person is liberated, the results of his good deeds will be distributed among those well disposed towards him, and the results of his sinful deeds will be distributed among his foes.
Thus good deeds without devotion or surrender cannot liberate us from the never-ending cycle of births and deaths. In the Charama sloka in the Bhagavad Gita, Lord Krishna says that He will get rid of everything that binds us, whether they are the effects of virtuous deeds or sins, if we surrender at His feet. Thus it becomes clear that while it is important to be virtuous, only bhakti or surrender can liberate us from the samsaric cycle.