In plain words
today I kill Bhīṣma, I protect you, let go, Arjuna, so saying, through the rain of my arrows, the God who comes driving on is my refuge.
‘The very Kṛṣṇa who is coming, saying, “I will protect you, I will kill Bhīṣma”, must protect me,’ he thought.
This is how devotees are today: ‘Alas! Rāma is coming to kill me. O Kṛṣṇa! Save me. O Īśvara! Save me,’ they say. If Kṛṣṇa Himself comes to kill, ‘O Rāma! Save me. O Sāī! Save me,’ so they call on the name of another deity. But Bhīṣma did not speak that way. ‘The very Kṛṣṇa who is coming to kill me must protect me. There is only one God. Who else is there? However many the forms, however many the names, God is only one. ‘One Lord, many names’: so Bhīṣma described Kṛṣṇa beautifully. In the same way, to slay the demonishness that has flared up in the humanness within Prakṛti, the power of Prakṛti itself must slay it. Prakṛti alone protects, and Prakṛti alone punishes. So that power of Prakṛti is Mother Durgā. The protection of that Durgā is Lakṣmī embodied. This Durgā Devī nourishes humanness and burns demonhood to ashes. Once the power called Durgā has driven demonhood away, the voice of God begins to be heard. Sarasvatī is the very form of that voice. So, to root out the impurity in the mind, bring forth divine feeling and make speech worthwhile, people have long worshipped the forms of these three, Durgā, Lakṣmī and Sarasvatī.
To long to see some other God while seeing the Paramātma in the form of Prakṛti is folly
Durgā is what roots out the impurity in the mind. Lakṣmī is what fosters good qualities once that impurity is rooted out. That is, Lakṣmī is what brings forth the feeling of the divine.