IX: 21

Chapter 9, Verse 21

"When their merit is spent,
They fall back into the mortal world.
Impelled by desire,
They achieve only that which will pass away.
They are caught
In the chain of personal desires
And continue to take birth."

Father Bede Griffiths:

Their good deeds have limited value.  When they have had their reward, then they must return.  Desire is the root of all limitations.  As long as you desire, you may get what you seek, but you will exhaust these things also.  Only when you go beyond desire altogether are you set free.  That is Liberation.

[The desire to always remember God and to act solely to please God is not the kind of desire that Krishna and Father Bede are talking about here.  This kind of special desire is a way of describing devotion for God.  This desire opens wide the gate to Liberation.]

Paramahansa Yogananda:

Good karma produces only a period of astral enjoyments.  Whether long or short, that period will come to an end.  However, those who single-heartedly love God and who work for God without desire for the fruits of action perform the true worship of Yoga practice.  They offer the self into the Self, purify their bodies and consciousness with the nectar of Divine Life-energy and win the Eternal Liberation.