And paradise is for such as love thee, heaven is for such as serve thee, the everlasting abode is for such as visit (thy tomb)! “Upon thee be El-Bahá! Upon thee be greeting and praise, O thou who hast suffered martyrdom in the path of God, and art submerged in the ocean of the mercy of God!
(‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v2, p. 384)
By “Heaven” is not meant this infinite phenomenal space, but “heaven” signifies the world of the divine kingdom which is the supreme station and seat of the Sun of Truth.
(‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá Abbas, Vol. 1, p. 192)
Heaven and hell are conditions within our own beings.
(Shoghi Effendi, Lights of Guidance, p. 519)
Paradise is the joy of knowing and loving God, as revealed through His Manifestation, thereby attaining to the utmost perfection of which one is capable, and, after death, obtaining entrance to the Kingdom of God and the life everlasting.
(Dr. J.E. Esslemont, Bahá’u’lláh and the New Era, p. 20)
To ‘get to heaven’ as you say is dependent on two things—faith in the Manifestation of God in His Day, in other words in this Age in Bahá’u’lláh; and good deeds, in other words living to the best of our ability a noble life and doing unto others as we would be done by. But we must always remember that our existence and everything we have or ever will have is dependent upon the Mercy of God and His Bounty, and therefore He can accept into His heaven, which is really nearness to Him, even the lowliest if He pleases. We always have the hope of receiving His Mercy if we reach out for it.
(Shoghi Effendi, Lights of Guidance, p. 209)
What is intended by the creation of heaven and earth in six days is a spiritual creation and a divine day, as prior to the creation of this heaven and earth there were no days and nights.
(‘Abdu’l-Bahá, from a previously untranslated Tablet, Extracts From The Bahá’í Writings And From Letters Of The Guardian And The Universal House Of Justice On The Old And New Testaments)