Swami Mukundananda: This is a very good question. Let’s break down these three words to answer it.
Bhukti is indulgence in material pleasures to satisfy the desires of the mind and senses. These desires are not limited to the human form. Instead, they continue into the higher regions of the seven layers of heaven—all the way to Brahmalok (the highest abode in the material realm). In other words, bhukti does not get us to Golok and nor to Shree Krishna.
Mukti is the desire for liberation. Many long for this mukti as they get tired of dealing with the stress of everyday life. Some see mukti as a means of escape. The drawback to this approach is that once the soul is liberated, it eternally loses its opportunity to serve its master, the Supreme Soul, Shree Krishna.
Now, let’s turn our attention to seva. Seva means to serve. We spend our lives serving the people we love—spouse or significant other, children, parents, siblings, and other family members and friends. Why? Because we love them. We love our children so we happily make sacrifices for them—we sacrifice our time, our meals, our sleep, our TV time, our happiness, etc. because we love them and instead do things that make them happy.
Similarly, if we were to identify with the soul, we would understand that as a part of Supreme Soul, it is our nature to serve the whole—the master, Shree Krishna. Once we engross ourselves completely in serving the Lord with our dhan, tan, man, then bhukti and mukti become insignificant puny desires that run after us. As we serve wholeheartedly, the happiness received by serving the Lord selflessly is unmatched by any material happiness.
Shree Maharajji, in his kirtan, states:
bhukti mukti nā de rādhe prem sudhā de
In other words, I desire neither bhukti (material pleasures) nor mukti (liberation). I only desire the nectar of Your sweet divine love (so that I may serve you endlessly).
And so, it is this level of seva that is the highest goal that we all should aspire to achieve.