Compare these verses on loving-kindness from the Suttas and Bible:
“Monks, for one whose awareness-release through good will is cultivated, developed, pursued, handed the reins and taken as a basis, given a grounding, steadied, consolidated, and well-undertaken, eleven benefits can be expected. Which eleven?
“One sleeps easily, wakes easily, dreams no evil dreams. One is dear to human beings, dear to non-human beings. The devas protect one. Neither fire, poison, nor weapons can touch one. One’s mind gains concentration quickly. One’s complexion is bright. One dies unconfused and, if penetrating no higher, is headed for the Brahma worlds.” — Mettanisamsa Sutta (AN 11.16)
Love is patient and kind; love does not envy or boast; it is not arrogant or rude. It does not insist on its own way; it is not irritable or resentful; it does not rejoice at wrongdoing, but rejoices with the truth. Love bears all things, believes all things, hopes all things, endures all things. As for prophecies, they will pass away; as for tongues, they will cease; as for knowledge, it will pass away. But love never ends.” — 1 Corinthians 13:4-8
I have my own observations to share. One may be very enlightened in knowledge and meditation. He may understand the purpose and evolution of the universe and the structure of consciousness. He may even be a great renunciant, have extraordinary intelligence or mystic powers. But none of these mean anything without mettā, loving-kindness.
Mettā is simply the greatest generator of good karma there is. Without mettā, all those other good qualities aren’t going to do you or anyone else any good. You won’t be able to advance in life without the intention to do good to others in a loving and affectionate way. And even if gifted with great knowledge or talent, you won’t be able to benefit others.
To lead to higher states, everything we do has to be rooted in mettā, anchored to mettā, powered by mettā; otherwise it is just concentrated or extended selfishness. That selfish intention short-circuits any good we are trying to do. We must sincerely and authentically act for the benefit of others, then all benefits will automatically be added unto us. That is my experience.
For example, we don’t need to do The Dharmasar Solution. We are already well-situated in self-realization. But to achieve any of our aims without also benefitting others would simply be impossible. So our activities in mettā are “cultivated, developed, pursued, handed the reins and taken as a basis, given a grounding, steadied, consolidated, and well-undertaken.” That is the real purpose of The Dharmasar Solution.