Be anxiously concerned with the

 

The All-Knowing Physician hath His finger on the pulse of mankind. He perceiveth the disease, and prescribeth, in His unerring wisdom, the remedy. Every age hath its own problem, and every soul its particular aspiration. The remedy the world needeth in its present-day afflictions can never be the same as that which a subsequent age may require. Be anxiously concerned with the needs of the age ye live in, and center your deliberations on its exigencies and requirements.
We can well perceive how the whole human race is encompassed with great, with incalculable afflictions. We see it languishing on its bed of sickness, sore-tried and disillusioned. They that are intoxicated by self-conceit have interposed themselves between it and the Divine and infallible Physician. Witness how they have entangled all men, themselves included, in the mesh of their devices. They can neither discover the cause of the disease, nor have they any knowledge of the remedy. They have conceived the straight to be crooked, and have imagined their friend an enemy.
Incline your ears to the sweet melody of this Prisoner. Arise, and lift up your voices, that haply they that are fast asleep may be awakened. Say: O ye who are as dead! The Hand of Divine bounty proffereth unto you the Water of Life. Hasten and drink your fill. Whoso hath been re-born in this Day, shall never die; whoso remaineth dead, shall never live.

Gleanings from the Writings of Bahá’u’lláh 
 Selection CVI  106