The question is simplistic, because surrender itself means to come to a state of doing nothing. We can understand this from the example of a newborn baby. A newly born baby does nothing, so her mother does everything for her. When she grows into a small child, she begins doing some of her tasks on her own, and so her mother lessens her responsibilities. When she grows further, she begins doing all her works herself, and her mother stops doing everything.
This example is illustrative of the process of surrender. As long as we possess the pride of performing our actions, God declares us as the doer, and we have to suffer the consequences of our actions according to the Law of Karma. When we surrender this pride, we become non-doers and God becomes the performer of our every action.
तेषां सततयुक्तानां भजतां प्रीतिपूर्वकं।
ददमि बुद्धियोगं तं येन मामुपयान्ति ते।।
According to this verse from the Bhagavad Gita, the Supreme Lord takes the responsibility for the welfare and liberation of surrendered souls. Therefore, if simply by giving up the pride of doing we are liberated from material bondage and rewarded with Divine Bliss, is this not the Causeless Mercy of God?
If we were required to do something to become beneficiaries of His Grace, then we could have had occasion to complain. However, what effort is involved in surrender? It is the process of giving up everything to attain everything. As long as a bird holds a piece of flesh in its beak, other birds chase it and do not allow it to rest in peace. The moment the bird gives up this piece of meat, i.e. surrenders everything, it attains peace. In the same way, surrender involves no effort at all. Without any effort if we receive Divine Grace, then that Grace is definitely causeless.
There is the famous incident of Draupadi’s surrender. When Draupadi was being disrobed in the assembly of the Kauravas, she first counted upon the protection of her husbands. When they remained silent, she relied upon the pious elders present in the assembly - Dronacharya, Kripacharya, Bhishma, Vidur etc. - to help her. When they too failed to take any step, she clenched her sari between her teeth. Yet, Shree Krishna did not come to her rescue. Finally, when Dushasan pulled her sari with a jerk, it slipped from her grasp. Now she surrendered herself totally to Shree Krishna, for she no longer had any faith in the protection of others, nor was she relying on her own strength. Immediately Shree Krishna offered complete protection, and she was saved. Shree Krishna declares in the Bhagavad Gita:
सर्वधर्मां परित्यज्य मामेकं शरणं व्रज।
अहं त्वां सर्वपापेभ्यो मोक्षयिषामि मा शुचः।
“O Arjun! Abandoning all concerns of religiosity and irreligiosity, simply surrender to Me. Then I, who dispense justice to all, will cease to be a mere judge. Bestowing My Grace, I will pardon all the sins of your innumerable past lives, and grant you liberation.” This is the immense Grace of God. This verse is the essence of Vedas and Upanishads.
In the world, even if a criminal surrenders himself to the law, he is made to suffer punishment for his past crimes. But God is so merciful that once you surrender to Him, He not only forgives all past deeds, but also bestows His Divine Bliss for the rest of eternity. If this is not causeless Grace, then what is?
Jagadguru Kripaluji Maharaj simplifies this by an example of a washer man. If a washer man were to clean your clothes and not charge you for it, you would say that he has done you a favor, even though the clothes could become dirty again. In comparison, when we surrender our mind and intellect to God, He cleans them forever, and that too, without any charge. In fact, even if we desire, we can never pay the price for God’s Grace. What we receive through Grace is Divine wealth, while what we give in return is only imperfect material goods. What need does God have for our material goods anyway? So, if God bestows His Grace upon our surrender to Him, it is His causeless mercy.