Sorry I confused you. I believe that God is reigning in heaven but both Jesus and Baha'u'llah and all the other Messengers of God are close to God in what Baha'u'llah referred to as the Supreme Concourse. None of the Messengers of God are literally 'reigning'; that is just an expression that denotes having 'all power' to affect souls in heaven and on earth. Didn't Jesus say in the New Testament that He will always be be with you in spirit even after He ascended to heaven? Baha'is believe the same thing about Baha'u'llah, and He promised that He would always be with us, beholding us from heaven, the realm of glory.
“Let not your hearts be perturbed, O people, when the glory of My Presence is withdrawn, and the ocean of My utterance is stilled. In My presence amongst you there is a wisdom, and in My absence there is yet another, inscrutable to all but God, the Incomparable, the All-Knowing. Verily, We behold you from Our realm of glory, and shall aid whosoever will arise for the triumph of Our Cause with the hosts of the Concourse on high and a company of Our favored angels.”
Gleanings From the Writings of Bahá’u’lláh, p. 140
Baha’u’llah sternly warned us
never to make any distinction between any of the Messengers of God (who are the Manifestations of His Cause) because they all arise to proclaim the same religion, since there is only one eternal religion of God. Baha’u’llah wrote that the works and acts of all the Manifestations of God were all ordained by God, a reflection of His Will and Purpose
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“Beware, O believers in the Unity of God, lest ye be tempted to make any distinction between any of the Manifestations of His Cause, or to discriminate against the signs that have accompanied and proclaimed their Revelation. This indeed is the true meaning of Divine Unity, if ye be of them that apprehend and believe this truth. Be ye assured, moreover, that the works and acts of each and every one of these Manifestations of God, nay whatever pertaineth unto them, and whatsoever they may manifest in the future, are all ordained by God, and are a reflection of His Will and Purpose. Whoso maketh the slightest possible difference between their persons, their words, their messages, their acts and manners, hath indeed disbelieved in God, hath repudiated His signs, and betrayed the Cause of His Messengers.” Gleanings From the Writings of Bahá’u’lláh, pp. 59-60
Although all the Manifestations of God are a refection of God's Will and Purpose, Jesus and Baha'u'llah had a greater mission earth than any other Manifestations of God. In the Baha'i scriptures, Baha'u'llah is referred to as the Greatest Name, but that does not mean He is "greater" than Jesus, it is just a title that was given to Him.
“Know that the attributes of perfection, the splendor of the divine bounties, and the lights of inspiration are visible and evident in all the Holy Manifestations; but the glorious Word of God, Christ, and the Greatest Name, Bahá’u’lláh, are manifestations and evidences which are beyond imagination, for They possess all the perfections of the former Manifestations; and more than that, They possess some perfections which make the other Manifestations dependent upon Them. So all the Prophets of Israel were centers of inspiration; Christ also was a receiver of inspiration, but what a difference between the inspiration of the Word of God and the revelations of Isaiah, Jeremiah and Elijah!” Some Answered Questions, pp. 149-150
Lord is a title that was given to Jesus in the scriptures. Jesus was a Manifestation of God, God's representative on earth, so He was referred to as Lord in the scriptures.
As a Manifestation of God, God's representative on earth, Baha'u'llah was referred to as the Lord of Hosts and God is referred to as the Lord of all names in the Baha'i scriptures.
“The fear of God is the shield that defendeth His Cause, the buckler that enableth His people to attain to victory. It is a standard that no man can abase, a force that no power can rival. By its aid, and by the leave of Him Who is the Lord of Hosts, they that have drawn nigh unto God have been able to subdue and conquer the citadels of the hearts of men.”
Gleanings From the Writings of Bahá’u’lláh, p. 272
“O kings of the earth! He Who is the sovereign Lord of all is come. The Kingdom is God’s, the omnipotent Protector, the Self-Subsisting. Worship none but God, and, with radiant hearts, lift up your faces unto your Lord, the Lord of all names. This is a Revelation to which whatever ye possess can never be compared, could ye but know it.”
Gleanings From the Writings of Bahá’u’lláh, p. 210