Gurudev, it is said that sattva (purity) is needed for the attainment of karma (action). But is rajas not required for karma? In my case if I do a lot of sadhana then I don't feel like doing anything.
There is another meaning of sattva – purity of intellect. Intellect is also called Sattva. But, to do any action rajoguna is required.
The body cannot be stable without the three gunas (Rajoguna, Tamoguna and Satoguna). There is a necessity for all three gunas in the body. Sattva will remain prominent in these. The rajoguna and tamoguna will stay suppressed, but they will be there for sure.
Once, a nuclear scientist had come here. He made a design and got it here. There were three spokes in his design, and he was saying – this world is held in balance by these three forces, which is why it has continued to exist all this time. Like the blades of a windmill, there are three spokes – they go up and down in sync. So with these three being present it will keep spinning again and again and again. In the same way, the world has always existed, and will always exist, till infinity, due to these three gunas.
Don't become lazy in the name of satoguna. Many times we think that due to sadhana there is abundance of satoguna, but if tamoguna increases then laziness comes. Be wary of this. So, along with satoguna, there should also be steadfastness in action.
When old age strikes, say you are 70 to 80 years old, then the quantities of rajoguna and tamoguna automatically decrease. Then sleep also abandons you. Then you sit and read, you engage in thinking, then also keep yourself busy.