Not to place any obstacle before a soul searching for Truth

No obstacle should be placed before any soul which might prevent it from finding the truth. Baha'u'llah revealed His directions, teachings, and laws, so that souls might know God, and not that any utterance might become an obstacle in their way. 

- ‘Abdu’l-Baha  (Words of 'Abdu'l-Baha, recorded by Dr. Edward C. Getsinger and cited in Star of the West, vol. 6; no.6, June 24, 1915)

The “worker in the cause of God is like a gardener”

One day we spoke of an active worker in this Cause, and 'Abdu'l-Baha said:   

"In this Cause, he who is active and who makes an effort will always meet with success. In worldly matters how often we see a man work hard for a lifetime and never achieve success. But the worker in the cause of God is like a gardener. The more attention he gives his garden, the more fruit will reward his efforts, or, like the traveler who has a great goal before him, no matter how hard the road, if he only keep on walking and is not turned aside by discouragements, he is sure, eventually, to reach his goal." 

-' Abdu'l-Baha  (Words of ‘Abdu’l-Baha, recorded by Helen Goodall and Ella Goodall Cooper during their pilgrimage in 1908; ‘Daily Lessons Received at Akka January 1908’)  

Stations of believers in the next world

Question: Will the stations of the believers continue to be different hereafter? 

'Abdu'l-Baha answered:

 "Yes, it will be necessarily so, for the Kingdom requires it. 

"The King appoints one to be his prime minister, another to be his greatest general, another a soldier, and so on from the highest to the lowest. If all were generals or all were soldiers, there would be no kingdom. 

"God created the mineral, the vegetable, the animal, and man. Had He created only man there would be no world."

- 'Abdu'l-Baha  (Words of ‘Abdu’l-Baha, recorded by Helen Goodall and Ella Goodall Cooper during their pilgrimage in 1908; ‘Daily Lessons Received at Akka January 1908’)

The “language of the Kingdom is one. It is the language of the hearts.”

…if there is a universal language, how excellent it would be. We could talk with each other. How excellent it would be. Compare this with all the world, the greatest means for love is a universal language. It creates love amongst mankind. For the language of the Kingdom is one. It is the language of the hearts. Hearts create amity with each other. In the same way that the language of the Kingdom is one, so also should the human tongues be one. Then it will be perfect, Hidden and Manifest, inner and outer, will become one.   

- 'Abdu'l-Baha  (Words of ‘Abdu’l-Baha, recorded by Harry Randall during his pilgrimage, 17 November 1919; ‘William Henry Randall, a Disciple of ‘Abdu’l-Baha’, by Bahiyyih Randall-Wincler) 

Under what circumstances kneeling and bowing are allowed

When ‘Abdu’l-Baha was leaving [the Shrine of the Báb], his honor Ibn-i-Asdaq, one of the famous teachers in Persia fell on his knees at ‘Abdu’l-Baha's feet. ‘Abdu’l- Baha said: ''According to the blessed command, it is not permitted to fall on the knees and bow down except before the blessed home and the tombs of Baha'u'llah and the Báb. Beware of deviating from the divine commands." 

(Recorded by Dr. Zia Baghdadi, December 6, 1913; ‘Star of the West, vol. 9, no. 2, April 9, 1918)

‘Abdu’l-Baha’s health and happiness

My health and happiness are in this, when I see the friends of God engaged in spreading the divine fragrances, arising to serve the Cause of God, forgetting every thought save that of teaching, casting into the corner of forgetfulness every matter but that of unity and harmony. Consider in every age what confirmation and assistance were received by those souls who devoted their time to serving the Cause and spreading the divine fragrances. On the contrary, those who were absorbed by personal interests or political affairs degraded not only themselves but their associates. Thus, in this day, the friends of God should see that all glory lies in teaching the Cause of God and that every happiness is found in the shadow of the Word of God. 

- 'Abdu'l-Baha  (Words of ‘Abdu’l-Baha after His return to the Holy Land from America, recorded by Dr. Zia Baghdadi, December 9, 1913; ‘Star of the West, vol. 9, no. 2, April 9, 1918)