"Devi will surely bestow mercy on me in this birth!" - what can help to get such necessary unshakable certainty of mind?

Binod Bihari das Babaji

(from introduction to "Sadhu Sadhu: a Life of Baba Sri Tinkadi Gosvami"):

Binod Bihari das Babaji: Many practitioners come to the holy land, Sri Vrindavan, with a strong desire and enthusiasm for worship in order to reach the lotus feet of Sri-Sri Yugala-kisora ​​(Divine Young Couple). In the first stage, the strong enthusiasm they have for solitary worship (bhajana) is clearly visible, and they cherish the hope of attaining the lotus feet of the Divine Couple in this life. But, after doing solitary worship for a long time, the hopelessness "I have not achieved anything" arises and covers the practitioner's mind. As a result, the practitioner's enthusiasm for bhajan gradually becomes weak. Then the sadhaka thinks, "If I have done so much bhajana in this life and achieved nothing, I doubt that anything at all will be achieved in this life!" This paradigm of thinking gradually takes root, and as a result, there is a weakness in bhajana. Then, with the mind attracted to worldly things, the sadhaka goes far from his goal.

If some student knows with certainty that he will not be able to pass the exam, he will naturally not study hard. Such a student will think, "If I can't pass the exam, what's the point of my studies?" In the same way, if one develops the mindset, “In this birth, I will not be able to reach the lotus feet of the Divine Couple, and who knows how many more births I will need for this,” then naturally, weakness, sloppiness in bhajana will arise. And if an unshakable certainty is in the mind of the sadhaka that "Radharani will surely bestow mercy on me in this birth," then the enthusiasm for solitary worship and longing will gradually increase. Such faith is absolutely necessary for attaining the lotus feet of the Lord.

For such faith to be strong, an example is needed. One needs the biographies of those personalities who received the grace of Radharani in this birth. How did they do bhajan? What did their detachment look like? What was their freedom from worldly desires? How did they lead their lives? How many kinds of obstacles and difficulties did they have to overcome? By giving such examples to practitioners, they will no longer fall prey to hopelessness. If weakness arises in bhajana, by watching such examples one will try to keep his mental strength unshakable.