Of course, as everyone knows, for a Christian, this linear, successive approach culminating with Islam does not correspond to our belief. If you picture pre-Christian revelation as a horizontal straight line, we view the event of the Incarnation (of God's becoming human) as such a major, world-shaking event that the previously flat straight line shoots up to infinity, much like two perpendicular lines at a corner as pictured above. With the Incarnation, we enter a new level, a new dimension. After the scandalously astounding event of the Incarnation, of God's freely choosing to humble himself out of love and become human, it is no longer possible to simply lengthen the straight horizontal line to reach an endpoint. (See St. Paul's Letter to the Philippians 2:5-11, below.) From the Christian point of view, the Incarnation makes that straight, horizontal line shoot upward, with no horizontal closure possible.
Philippians 2 (English Standard Version):
5 Have this mind among yourselves, which is yours in Christ Jesus,  6 who, though he was in the form of God, did not count equality with God a thing to be grasped, 7 but made himself nothing, taking the form of a servant,  being born in the likeness of men. 8 And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross. 9 Therefore God has highly exalted him and bestowed on him the name that is above every name, 10 so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, 11 and every tongue confess that Jesus Christ is Lord, to the glory of God the Father.