Purport

In earlier Chapters, Bhagvan Shri Krishna described the processes of Ashtanga Yoga, Tapasya, karma, and Janana(Knowledge) using which a human can attain Moksha.

Attaining Moksha is one thing but knowing God is another. To understand God and true nature is even more tedious. In earlier Shlokas Bhagvan Shri Krishna hence asked Arjuna to focus on what is going to be described. In This Shloka Bhagvan Shri Krishna explains the hard fact of how rare is among Humans to Know God and understand his true nature and potency?

One out of thousands tries to achieve perfection in Spiritual practices that are siddhi. And one out of thousand of perfected(siddha) knows God in reality. That explains that many a time even perfected persons may not have enough desire and resolve to know God.

Most of the time only a few among us are able to try to know God and that most of us are not able to see God. To know God one needs true love and dedication.