5.25, Sloka 25, Chapter 5:
Another core activity of people who are called “Rishi” is given here. They are those set of people whose sins have been eradicated or removed or become weak, whose doubts have been dispelled about absolute truth, and are actively involved in the welfare of others. Such type people as they are involved in welfare, they attain the Brahma- nirvana, which is the realization of absolute truth.
5.26, Sloka 26, Chapter 5:
In this sloka Lord Krishna again gives affirmation that it is quite possible to realize the absolute truth in this very world. He says it is not only possible in the present world but also carried to the next existence.
The prequalifications are, the person should subdue his/her mind and should be free from desire and anger.
The concept of desire and anger keep repeating most of the time in Geetha and every time whenever they come, Lord Krishna requests us to be free of them.