To answer this question, we need a little background information.

Ida, Pingala, and Sushumna are the three energies or three kinds of breaths every human being possesses.

Ida, the breath coming from left nostril (cools the body) represents Goddess Parvathi who is known as kriya shakti, the power of physical energy.

Pingala, the breath coming from right nostril (warms the body) is represented by Goddess Lakshmi. She represents ichha shakti, the power of desires.

Sushumna, the balanced breath between left and right nostril (which maintain the equilibrium between warmth and coolness), represents Saraswati, who in turn represents knowledge.

These three powers, being the consorts of Shiva, Vishnu, and Brahma respectively are the three energies on which this world runs.

The Trinity, or the group of three Gods, rules this universe with the help of the consorts who represent three energies.

Lakshmi, the ichha shakti or the power of desires, rules the universe mainly.

ICHHA SHAKTI IS ALSO KNOWN AS WILLPOWER!

IF there is no desire, nothing moves!

If Lord Vishnu didn't possess the desire to grace the souls by creating a training arena for all of them to perfect themselves for their respective destinations, this universe would not have been created by him.

So, the main energy on which this world depends is desires of different souls. That is what makes us all do different things.

Desires make the world tick!

Desire -------->knowledge--------->Action

So, earlier, all were worshiping the Trinity and the three Goddesses.

But, in the age of Kali, or in the present era known as Kaliyug, PHYSICAL might is not sufficient to protect the good ones and to succeed.

That is why Indian scriptures bid that :

We need to worship Vinayaka, aka Ganesha or Ganapati, and Chandi (i.e. be very persistent to achieve anything or be very clever-wise as different from Intelligence- in Kaliyuga), especially Ganesha to succeed in life.

And also that a Sangha or “group of people held together by some purpose” is a very strong power.

As, in present age or times, good people do not wield much power, they need to survive with extreme wisdom which is represented by Lord Ganesha who is none other than Lord Vishnu born as son of Parvathi.

If they try to be Extremely Honest and stand straight, as Chanakya states - it is the upright trees that get cut or fall first.

Also scriptures bid that before we begin any auspicious or important work, we should first pray/worship Lord Vighnesha or Ganapati because he removes the obstructions/obstacles in one's path.

Practically speaking, we should listen to various people, our near ones or far ones, friends or foes, and think critically before starting any important task. Ganapati is the symbol or God of wisdom.

That is the relationship between the three powers which rules the world now. Desires (will power), Wisdom, and Knowledge are represented by the the threesome!

If you simply want a different perspective, Lakshmi is the mother of Saraswati who is the mother of Parvati and finally Parvati is the mother of Ganesha.

Lakshmi also represents Good luck. However. much one works hard, without the grace of God or good luck bearing Goddess, nothing remains with us.

One needs knowledge to create like Brahma, so Saraswati is his wife.

Before we start any auspicious task, we need to pray Lord Ganesha, without whose blessings many obstructions may spoil the tasks.

In sum, the three deities are the Governing powers now being presided over by Lord Ganesha in the Era of Kali. You might as well remember that Lokamanya Tilak used Ganesha chaturthi puja (the celebration of Lord Ganesh's birthday) to unite Indians.

You may learn more about nadis in the below link. By James Bailey.

Discover the Ida and Pingala Nadis

What is the relationship between Lord Ganesh, Goddesses Laxmi, and Saraswati?

Very Interesting!