O people of Bahá!

"O people of Bahá! Ye are the dawning-places of the love of God and the daysprings of His loving-kindness. Defile not your tongues with the cursing and reviling of any soul, and guard your eyes against that which is not seemly.
Set forth that which ye possess. If it be favourably received, your end is attained; if not, to protest is vain. Leave that soul to himself and turn unto the Lord, the Protector, the Self-Subsisting.
Be not the cause of grief, much less of discord and strife. The hope is cherished that ye may obtain true education in the shelter of the tree of His tender mercies and act in accordance with that which God desireth. Ye are all the leaves of one tree and the drops of one ocean."

Tablets of Bahá’u’lláh, The eighth Ishráq

God’s purpose in sending His Prophets unto men is twofold.

"Every Prophet Whom the Almighty and Peerless Creator hath purposed to send to the peoples of the earth hath been entrusted with a Message, and charged to act in a manner that would best meet the requirements of the age in which He appeared.
God’s purpose in sending His Prophets unto men is twofold.
The first is to liberate the children of men from the darkness of ignorance, and guide them to the light of true understanding. The second is to ensure the peace and tranquility of mankind, and provide all the means by which they can be established."

Gleanings From the Writings of Bahá’u’lláh P 80

The measure of the revelation of the Prophets ...

The measure of the revelation of the Prophets of God in this world, however, must differ. Each and every one of them hath been the Bearer of a distinct Message, and hath been commissioned to reveal Himself through specific acts.
It is for this reason that they appear to vary in their greatness.
Their Revelation may be likened unto the light of the moon that sheddeth its radiance upon the earth. Though every time it appeareth, it revealeth a fresh measure of its brightness, yet its inherent splendor can never diminish, nor can its light suffer extinction. It is clear and evident, therefore, that any apparent variation in the intensity of their light is not inherent in the light itself, but should rather be attributed to the varying receptivity of an ever-changing world.

Gleanings From the Writings of Bahá’u’lláh P.80

"Observe My commandments, for the love of My beauty."

"Say: From My laws the sweet-smelling savour of My garment can be smelled, and by their aid the standards of Victory will be planted upon the highest peaks. The Tongue of My power hath, from the heaven of My omnipotent glory, addressed to My creation these words: "Observe My commandments, for the love of My beauty." Happy is the lover that hath inhaled the divine fragrance of his Best-Beloved from these words, laden with the perfume of a grace which no tongue can describe. ...
Think not that We have revealed unto you a mere code of laws. Nay, rather, We have unsealed the choice Wine with the fingers of might and power. To this beareth witness that which the Pen of Revelation hath revealed. Meditate upon this, O men of insight!

Bahá'u'lláh"
The Kitab-i-Aqdas, pp. 20-21