“True joy comes from the tranquility of heart, and this state comes from faith!”

Then He [‘Abdu’l-Baha] spoke at length of the "composure of heart," or "tranquility of the soul." "This", He said, "is a state of true faith which gives man such assurance and conviction of God's bounty, that all the trials and sufferings of this earth cannot affect him." Speaking of true joy and happiness. He said in part: "… True joy comes from the tranquility of heart, and this state comes from faith! Praise be to God who gave us tranquility of heart! This is why we are always happy. I pray and supplicate to the Beauty of Abha to bless all the servants and maid-servants with true happiness resulting from the tranquility of heart." 

- 'Abdu'l-Baha  (Words of ‘Abdu’l-Baha, recorded by Ali-Kuli Khan during his pilgrimage in 1906)

How to overcome the tendency of seeing the faults of others

As to backbiting, the House of Justice points out that learning not to concern oneself with the faults of others seems to be one of the most difficult lessons for people to master, and that failing in this is a fertile cause of disputes among Baha'is as it is among men and women in general. In Star of the West. Volume 8, No. 10, on page 138, there is a record of a reply given by 'Abdu'l-Baha in a private interview in Paris in 1913. He was asked “How shall I overcome seeing the faults of others - recognizing the wrong in others?” and He replied: “I will tell you. Whenever you recognize the fault of another, think of yourself: What are my imperfections? - and try to remove them. Thus you will grow, become more perfect. You will overcome self, you will not even have time to think of the faults of others…"

- The Universal House of Justice  (From a message written on behalf of the Universal House of Justice to an individual believer, 13 August 1980; compilation: ‘Lights of Guidance’)

“The Word of God…is the master key for the whole world”

The Word of God is the king of words and its pervasive influence is incalculable. It hath ever dominated and will continue to dominate the realm of being. The Great Being saith: The Word is the master key for the whole world, inasmuch as through its potency the doors of the hearts of men, which in reality are the doors of heaven, are unlocked. No sooner had but a glimmer of its effulgent splendour shone forth upon the mirror of love than the blessed word ‘I am the Best-Beloved’ was reflected therein. It is an ocean inexhaustible in riches, comprehending all things. Every thing which can be perceived is but an emanation therefrom. High, immeasurably high is this sublime station, in whose shadow moveth the essence of loftiness and splendour, wrapt in praise and adoration. 

- Baha’u’llah  (‘Tablets of Baha’u’llah revealed after the Kitab-i-Aqdas’)

Secret to happiness

Human happiness is founded upon spiritual behaviour … 

- ‘Abdu’l-Baha  (‘Selections from the Writings of ‘Abdu’l-Baha’)

“The Bahá'í Teachings… raise marriage to the status of a divine institution”

The Bahá'í Teachings do not only encourage marital life, considering it the natural and normal way of existence for every sane, healthy and socially-conscious and responsible person, but raise marriage to the status of a divine institution, its chief and sacred purpose being the perpetuation of the human race -- which is the very flower of the entire creation -- and its elevation to the true station destined for it by God. 

- Shoghi Effendi  (From a letter written on behalf of Shoghi Effendi to an individual believer, dated 15 April 1939; The Compilation of Compilations, vol. I, Preserving Baha’i Marriages)