A positive state of mind is characterized by positive emotions like love, peace and joy. A negative state of mind is characterized by negative emotions like anger, hatred, ill will, fear, depression, anxiety and so on.
Buddhism: In Buddhism, a positive state of mind is exemplified by Four Brahmaviharas: loving-kindness, compassion, empathetic joy and equanimity. These are also called 'The Four Immeasurables' because they cannot be measured in terms of physical dimensions like length and time duration.
Sikhism: In Sikhism, a positive state of mind is called Charhdi Kala (a mental state infused with optimism and joy). One who is in a permanent state of Charhdi Kala is a Brahma Gyani. The virtuous conduct of a Brahma Gyani is described in several verses in The Sukhmani Sahib.
Advaita Vedanta: Ashtavakra Gita is a classic text that explains the worldly conduct of somebody who has understood non-duality and practices non attachment.
Some spiritual texts use the adjective 'infinite' to qualify positive emotions: infinite love, infinite joy, infinite compassion, and so on. Infinitude basically means 'always' ('no matter what situation we face').
Negative states of mind are sometimes called enemies or thieves or weaknesses. These thieves and enemies are not external; they are internal (mental shortcomings). Whey are they called thieves and enemies? Because they steal our peace of mind, they destroy our peace of mind.
Sikhism lists Five Thieves ('Panj Dosh' or 'Panj Vikar' or 'Five Weaknesses'): kaam (lust), krodha (anger), lobh (greed), moha (attachment) and ahankar (pride).
Hindu theology mentions six enemies: kaam (lust), krodha (anger), lobh (greed), moha (attachment), mada (pride) and matsarya (jealousy). Collectively, these six are called Arishadvargas.
In order to experience a positive state of mind, we have to invest effort in overcoming the internal enemies / thieves / weaknesses listed above. Proper names like Arijit, Aparajit and Ripudaman reflect conquest over these enemies.
When we interact with others, we spread our internal state of mind. If we are positive, we spread positivity to others; we uplift them. If we are negative, we spread negativity to others; we bring them down. To understand this, recall occasions when you were in the presence of a joyful or a kind-hearted person. How did that interaction influence you? Now recall interactions with somebody experiencing grief or anger or anxiety or fear. How did that interaction affect you?
Buddhists classify actions into wholesome and unwholesome.
Wholesome actions uplift us and others. Such actions are done with a positive state of mind (love, peace n joy). Such actions maintain or increase our positivity. They also influence other people: they are uplifted by becoming loving, peaceful and joyful.
Unwholesome actions bring us and others down. Such actions are done with some negativity in the mind: anger, hatred, ill will, fear, anxiety, depression, jealousy, and so on. Such actions maintain or increase our negativity. These actions influence others negatively by promoting negativity in others.
Interestingly, there is no concept of the doer benefiting at the cost of others, or the doer losing out to others. In other words, there is no game theoretic framework for decision making. An action either benefits everybody or harms everybody, where 'everybody' includes the doer.
Joseph Campbell shared the story below in one of his lectures:
During the 10-day Vipassana Course, lectures by S N Goenka are played every day at 7pm. In one of these lectures, S N Goenka gave the following example. In India, when somebody is upset with another person, they may call that person a pig or a donkey or a dog, with anger and contempt in their heart. A mother may also call her toddler the same names, but she in a loving tone. So even though the statements are the same in both situations, the internal state of mind is different: anger vs love. The internal state of mind is what makes an action wholesome or unwholesome, not the action itself.
In the lecture The Way of Love, Swami Sarvapriyananda explains that the practice in Bhakti Marga is to do all voluntary actions as service to God and to perceive all involuntary actions as manifestations of God, with peace and joy in our heart. Involuntary bodily actions include breathing. Voluntary bodily actions include self care (bathing, sleeping, eating and so on), our daily work, our leisure activities, and other mundane activities. The state of mind when doing these actions is important: if done as acts of service, we get to experience peace and joy. The involuntary actions are happening by themselves — these are manifestations of God. With practice, even voluntary actions can be seen similarly, as manifestations of God.
A couplet which beautifully encapsulates the gist of Karma Yoga is:
In Roman script:
Translation:
Some people mistakenly believe that spiritual pursuits amount to withdrawal from 'normal', 'regular' life and spending time in a forest, away from human contact. While that may be the way of life for some people, especially towards the end of their lives, that's not the recommendation of any spiritual system.
The real goal of meditative practices is to live a 'normal', 'regular' life as a functioning member of society and to keep refining the main practice in our day to day life. Activities like going to a forest or going to meditation retreats in sylvan settings do have their merits: they are short term sojourns which help us learn the main technique and sharpen our practice.