Our own endeavours can only take us to a certain level but ultimate goal will be attained only by the mercy of Vaishnavas and mercy of Krishna.
The Lord is always worthy to be the master of the surrendered soul, for He is the ocean of mercy.
Srimad Bhagavatam 4.8.46,
Krishna does not agree to award devotional service to merely anyone. Krishna can easily offer a person material happiness or even liberation, but He does not agree very easily to award a person engagement in his devotional service. Devotional service can in fact be attained only through the mercy of a pure devotee. — The Nectar of Devotion, Page 14.