Well, from the Wikipedia article, this part shows a fundamental misreading of Jesus: "In his speech, Iqbal emphasised that unlike Christianity, Islam came with 'legal concepts' with 'civic significance,' with its 'religious ideals' considered as inseparable from social order: 'therefore, the construction of a policy on national lines, if it means a displacement of the Islamic principle of solidarity, is simply unthinkable to a Muslim.'"
Christianity definitely comes with legal concepts with civic significance and also comes with religious ideals considered inseparable from social order. What Iqbal ignored there is the non-coercive aspect of Christianity/Jesus.
As for Rumi's observation (Iqbal was a disciple of Rumi, although separated by centuries) that "Creative love, or the urge to rejoin the spirit to divinity, was the goal towards which every thing moves" (according to the Wikipedia entry about him); of course, it's not true. It is not the goal of Satan or Satan's false prophet and eternal followers, fallen souls who will never repent.
It appears, as always, that the point of separation is semantical. The true meaning of love is not the same for Muslims and Christians. For the Muslim, love allows human-on-human violence. For the Christian, it does not. It's a huge difference that is reflected in the outward world.
A Christian does not subscribe to the "all religious paths lead to God or the divine" school of thought. For the Christian, Jesus Christ's message is the one and only path to God. He said, "I am the way, the truth, and the life: no man cometh unto the Father, but by me."
In, "The Reconstruction of Religious Thought in Islam"; "Knowledge and Religious Experience," Muhammad Iqbal writes, "The great point in Christianity is the search for an independent content for spiritual life which, according to the insight of its founder, could be elevated, not by the forces of a world external to the soul of man, but by the revelation of a new world within his soul."
"... not by the forces of a world external to the soul of man, but by the revelation of a new world within his soul." Actually, in Christianity, it's both.
He goes on to say, "Islam fully agrees with this insight and supplements it by the further insight that the illumination of the new world thus revealed is not something foreign to the world of matter but permeates it through and through."
The definitions of matter and substance were not addressed before he made this statement. The fact is that the New Earth and New Heaven of Jesus's Good News (Gospel) conflate. This is the real matter. Contrary to Iqbal's position, Christianity does not hold that the ideal and real are different. Iqbal apparently believes that this plane of existence is the real. For the Christian, this plane until perfected is below the real that is the ideal. Here you see the semantical difficulties.
Then comes the statement by Mohammed that "time is God." For the Christian, time is not God proper. Eternity is. Eternity transcends the Einsteinian. Before matter (whether termed chaotic or not) was and remains God. That's the Christian knowledge.
Mohammed also said, "See ye not how God hath put under you all that is in the Heavens...." (Qur'an 31:20)
However, the Qur'an also says that Heaven is off bounds to the spirits informing Mohammed. Such was never the case concerning Jesus.
Iqbal writes, "It is our reflective contact with the temporal flux of things which trains us for an intellectual vision of the non-temporal."
However, he had just said that God is time in the temporal (he calls it serial time) sense-meaning. I see no shift in context here with him but rather a plain mistake.
"The 'heart' is a kind of inner intuition or insight which, in the beautiful words of Rumi, feeds on the rays of the sun and brings us into contact with aspects of Reality other than those open to sense-perception."
Prior to this though, Iqbal made clear (he thought) that without the physical senses that even the atheists define, there would be no knowledge or perception. However, there is God, unless Iqbal means to admit at the same time that the divine can see without flesh eyes and hear without flesh (materially manifest) ears.
This is not an area where I will say that he's in error or self-contradictory but rather say that I reserve judgment since he might flesh this out elsewhere. I am aware that he is a Sufi and is speaking often about the mystical. He just jumped right into this though without explaining his terms.
With Jesus, there are abundant metaphors and similes.
Then, Iqbal goes into what apparently seems an attempt to address where matter leaves off and the spirit begins. I won't argue with that. However, he writes, "The Prophet of Islam was the first critical observer of psychic phenomena."
This is a sweeping and unfounded statement. What was Jesus dealing with if not the spirit and soul, which is the meaning of the term "psychic"?
At this point, I am getting the direct impressions that Iqbal barely read the Gospels if at all.
Iqbal does begin though to work to flesh out his views concerning matter versus the mystical. I'm waiting for the spiritual to truly enter into his discussion, unless I'm supposed to have inferred it. Knowing that he is a Sufi, I realize that his ecstaticism (whirling dervish) is something apart from Jesus's spirituality.
"Since the quality of mystic experience is to be directly experienced, it is obvious that it cannot be communicated."
Ah, I agree with that.
"...while religion starts with feeling, it has never, in its history, taken itself as a matter of feeling alone and has constantly striven after metaphysics."
However, there is metaphysical feeling. Iqbal appears to have made that point already. Again, this is semantical difficulty. I sympathize with the difficulty. Semantical theology is a main focus of my theology.
"Psychologically speaking, all states, whether their content is religious or non-religious, are organically determined."
Here again, I raise God. God is beyond organic in this sense even while God can manifest as flesh at God's will.
Quoting the Qur'an: "We have not sent any Apostle or Prophet before thee among whose desires Satan injected not some wrong desire, but God shall bring to nought that which Satan had suggested. Thus shall God affirm His revelations, for God is Knowing and Wise" (22:52).
Is "injected" the best translation there? Satan attempted to inject into Jesus wrong desire, but Jesus did not fall but rather rose above Satan and overcame the world to save it. Now I'm speaking the language of the revelation of Jesus to you there.
The last five paragraphs are too easy on Freud. Of course, he was writing this in the 1920's and didn't necessarily have much information on Freud vis-a-vis Freud's problems and issues that still go largely unaddressed (hush-hush in lower academic circles).