The problem with positive thinking and conventional law of attraction teachings is that while they attempt to shift the contents of consciousness from negative states to positive, they still encourage identification with the contents of consciousness, i.e. thoughts, rather than placing awareness on consciousness itself. It is the identification with our thoughts, whether they are positive or negative, that poses the barrier to moments of enlightenment.
I'm not arguing that it doesn't serve us to shift from negative to positive mental states. Needlessly worrying about circumstances we can't control or assuming the worst of other people is associated with psychological and physiological stress that is harmful over time. But it is just as important for our perception of the negative to broaden as it is to persuade ourselves to think positively. In fact, if the mere awareness that we are thinking "negatively" isn’t sufficient to create a shift, even a subtle one, to a state of acceptance and allowing, then no amount of coercive thinking will help. It may seem that we are momentarily able to think more positively, which is what the law of attraction seems to emphasize, but we will ultimately continue to reinforce the identification with thought itself. It is the awareness of thinking that’s important, not the forced positive (and often magical) thinking that law of attraction practitioners engage in.
It may help people to hear that by being stuck in a scarcity mindset they will be doomed to perpetuate it, in so far as it makes them aware of their thoughts in totality. But the message that they must identify mentally with abundance still encourages them to remain firmly attached to thinking regardless. All thinking - positive and negative - is similar in that thoughts are merely the contents of consciousness and not consciousness itself. One can only get so far with this approach if the goal is to live a conscious or spiritual life. It is recognizing the contents of consciousness without judgment or attachment that will prevent the identification with any particular thought pattern. Only then can one truly be free; for the essence of pure consciousness isn’t necessarily that of “abundance” or “positive" thinking, but of freedom.
When we make decisions from a place of complete freedom, we naturally gravitate towards peace and bliss. We act in ways that align with our highest good. We calm our nervous systems by allowing attachments to fall away. Freedom in this context implies the release from identifying with our thoughts. The caveat is that by choosing to detach from our negative thoughts, we also separate from our positive thoughts as well. Both states are thinking; they are both the contents of our consciousness.
The human mind also has a tendency towards fallacy and confabulation. What may seem positive on the surface may very well have roots in fear and anxiety. Since we can't be selective about how we identify, we can be selective about where we place our awareness. We can absolutely choose to focus on positive states but we must be careful to do so without identifying with them.
This won’t make sense to those who do not know what it’s like to not identify with their thoughts. It may be especially problematic for those entrenched in the belief that the problem is with their negative thoughts and emotions. These are not the root problem - it’s identifying with them that causes the suffering. Not identifying with negative thoughts or emotions is not the same as not having them at all, as they are a reflex of the mind and our habits. And of course, we do need to change our bad habits. But we need to understand that thoughts, whether positive or negative, are not who we are.
It's an excellent first step to recognize the limitations of negative thoughts and to want to change them. But what most desire from the spiritual path is to experience their own consciousness; to know themselves. In this pursuit, one must eventually arrive at the paradox that the Self is neither thought nor emotion. In fact, the more one tries to pinpoint the Self, the more one fails. Thus, it can't be the single minded devotion to the positive that allows for self-discovery.
This is ultimately the spiritual work we must do. To reflect, observe and experience the state of our own consciousness so that we can know freedom. It is this state that allows experiences of transcendence, empathy, and compassion. These are the so-called "positive" feelings that form the foundation of a fulfilling and enriching life, in which we struggle less with our thoughts and instead watch them transform themselves through our awareness.