The inability to forgive is intimately linked to the cycle of suffering, as explained by The Twelve Nidanas of Dependent Origination in Buddhism. These twelve links illustrate the cause-and-effect relationship of suffering and how karmic tendencies and habits can perpetuate this cycle.

The first link, Ignorance (avijja), represents a lack of understanding of the true nature of reality, including the impermanence and interconnectedness of all things. Due to this ignorance, the person forms mental habits or patterns of holding grudges, and being unable to forgive, signifying the second link, Mental Formations (sankhara). These negative habits condition the persons consciousness (viññana), making them prone to holding onto past hurt and grievances.

The fourth link, Name and Form (nama-rupa), represents the persons psychological and emotional makeup that manifests as an inability to forgive. The persons sense organs (sight, hearing, smell, taste, touch, and mind) interact with the external world, known as the fifth link, Six Sense Bases (salayatana), and any stimulus that triggers the memory of hurt and resentment can cause negativity by reactivating past memories.

The sixth link, Contact (phassa), refers to encountering such an activating stimulus, leading to the seventh link, Feeling (vedana), which creates an unpleasant experience like anger, pain, or sadness. This unpleasant feeling leads to the eighth link, Craving (tanha), which makes it difficult to let go of resentment and seek revenge, leading to the ninth link, Clinging (upadana). Clinging to resentment prevents forgiveness, reinforces the karmic tendencies, and perpetuates the cycle of suffering.

The tenth link, Becoming (bhava), signifies the personality traits that develop from the inability to forgive and reinforce the cycle of suffering. This personality tendency can manifest in the behavior of seeking revenge, avoiding those who remind them of past hurt, or other negative reactions. Inevitably, this personality tendency creates the eleventh and twelfth links, Birth (jati) and Old age and Death (jara-marana), respectively, bringing physical, emotional, and mental suffering.

To break the cycle of the inability to forgive, one needs to understand the Twelve Nidanas of Dependent Origination and practice mindfulness, positive thoughts, and understand the impermanence and interconnectedness of all things. Practicing mindfulness can make one conscious of past hurt, recognize and address triggers, and avoid reactivating harmful behaviors. Positive thoughts and cultivating loving-kindness towards oneself and others can weaken the mental pattern of holding grudges and foster forgiveness.

Understanding the impermanence and interconnectedness of all things can reinforce the idea that holding onto resentment and refusing to forgive only leads to suffering, hindering the natural process of life. By being mindful of the triggers causing negative emotions, one can address such emotions skillfully and cultivate healthy emotional patterns, leading to a more peaceful and fulfilling life.