The ultimate goal that human beings seek it, is achievement to happiness, but there are different opinions on its extension. In the Islamic mysticism, the path towards happiness passes through the spiritual journey -Tariqat- and the end of spiritual journey is expressed by such various words and idioms as Paradise, Vision of God, Annihilation in God and Spiritual Ascension. The final goal of the mystical journey, according to Ibn ‘Arabi’s school, is the gnosis of Unity of Existence -Wahdat-i Wujud- or in the other words self-knowledge -Khod Shenasi-.A novice mystic, at the first stage of his journey, does not have any gnosis towards himself and God. He at the end of his journey knows his self and recognizes that his own self in nothing but God. The spiritual journey of mystic is similar to Mohammad(P.B.U.H)’s ascension to Heaven: A mystic at first gains the knowledge of certainty -‘Elm al-yaqin- which has been acquired through deliberation on the Quran and prophetic traditions, then in his ascent, reaches the stages of eye of certainty or the unity of witness ‘Eyn al-Yaqin ya Wahdat-i Shohud- and after that the truth of certainty- Haq al-Yaqin-In the present paper an attempt has been made to examine, compare and analyze, the mentioned themes and subjects.