One can only attain virtue if his intentions are pure and his heart is untainted by spite and rancour.
Almighty Allah says: “The day whereon neither wealth nor sons will avail. Except him who brings to Allah a clean heart (clean from Shirk -polytheism- and Nifaq -hypocracy-).
Similarly, Ibn Tamiyah said: “The religion (Islam) in its entirety is virtue; the better a person’s conduct, the more religious he is.” His level of Eeman will be elevated and he will attain peace, contentment and tranquillity.
Because of this, the teachings of Prophet Muhammad (S) are the best source of learning for those who follow his methodology; i.e. the methodology of adopting leniency, pardoning others, forgiving when one is capable of retaliation, and giving up grudges, spite and revenge.
This book discusses:
Positive thinking and the Subconscious Mind.
Response of Believers in Hardship: Acceptance and Patience
Behaviour of the Companions under Infliction
Means of Reconciliation with people who have caused us Harm
Pardon and forgiveness