God is the great Physician Who alone can rightly diagnose the world’s sickness and prescribe the appropriate remedy. The remedy prescribed in one age is no longer suitable in a later age, when the condition of the patient is different. To cling to the old remedy when the physician has ordered new treatment is not to show faith in the physician, but infidelity. It may be a shock to the Jew to be told that some of the remedies for the world’s sickness which Moses ordered over three thousand years ago are now out of date and unsuitable; the Christian may be equally shocked when told that Muḥammad had anything necessary or valuable to add to what Jesus prescribed; and so also the Muslim, when asked to admit that the Báb or Bahá’u’lláh had authority to alter the commands of Muḥammad; but according to the Bahá’í view, true devotion to God implies reverence to all His Prophets, and implicit obedience to His latest Commands, as given by the Prophet for our own age. Only by such devotion can true Unity be attained. The Supreme Manifestation Like all the other Prophets, Bahá’u’lláh states His own Mission in the most unmistakable terms. In the Lawḥ-i-Aqdas, a Tablet addressed especially to Christians, He says:— Surely the Father hath come and hath fulfilled that which you were promised in the Kingdom of God. This is the Word which the Son veiled when He said to those around Him that at that time they could not bear it. But when the stated time was ended, and the Hour arrived, the Word shone forth from the Horizon of the Will. Beware, O Concourse of the Son (i.e. Christians)! Cast it not behind you, but hold thereunto. It is better for you than all that which is before you! ... Verily, the Spirit of Truth is come, to guide you into all Truth. Verily, He speaketh not from Himself, nay, but rather from the All-Knowing and Wise. He is the One Whom the Son hath glorified.... Abandon that which is before you, O people of the earth, and take that which is commanded you by Him Who is the Powerful, the Faithful. And in a letter to the Pope, written from Adrianople in 1867, He says:— Beware lest celebration hinder you from the Celebrated and worship hinder you from the Worshipped One! Behold the Lord, the Mighty, the All-Knowing! He hath come to minister to the life of the world, and for the uniting of whatever dwelleth therein. Come, O ye people, to the Dawning-place of Revelation! Tarry not, even for an hour! Are ye learned of the Gospel, and yet are unable to see the Lord of Glory? This beseemeth you not, O learned concourse! Say then, if ye deny this matter, by what proof do you believe in God? Produce your proof....