In the past, the question of whether Muslims and Christians worship the same God was not uncommonly given a negative answer - in other words, "Allah" was taken to be a conceptual idol. Nowadays missionaries tend to be more cautious in answering this question, and generally do so in the affirmative, albeit with some reservations. Geisler and Saleeb sum up the general feeling with a quote from Cragg: "The differences, which undoubtedly exist, between the Muslim and the Christian understanding of God are far-reaching and must be patiently studied. But it would be fatal to all our mutual tasks to doubt that one and the same God over all was the reality in both" (p. 14). Evidence adduced in support if this includes the testimony of converts from Islam to Christianity, who usually feel that there is some continuity in their relationship with God before and after their conversion, and the fact that Arab Christians use the word "Allah" for God. (Geisler and Saleeb, "Answering Islam", p.15; Goldsmith, "Islam and Christian Witness", p. 15; Parshall, "The Cross and the Crescent", pp. 23-4)
The theme of God's love is prominent in the Bible - especially the New Testament - and in Christian thought, and it is therefore a theme to which Christians often refer when relating to Islam. It is often acknowledged that the idea of God's closeness or even His love is not absent from the Qur'an; several missionaries cite the Qur'anic verse which describes God as being nearer to man than his jugular vein which describes God as being nearer to man than his jugular vein (50:60). (Geisler and Saleeb, "Answering Islam", p.27; Goldsmith, "Islam and Christian Witness", p. 89; Moucarry, "Islam and Christianity at the Crossroads", p. 47) However, God's love in Islam is felt to be mitigated either by not being prior to His other attributes, or by being qualitatively different to His love in Christian teachings. Goldsmith expresses the former view when he says: "while the Christian will insist that God's power is subject to his love and holiness, Islam will feel that God's love and holiness must never contradict his sovereign power" (p.90). Brown acknowledges that Muslims, like Christians, see God as "living and personal", but finds that the emphasis in the Qur'an is on His omnipotence and sovereignty rather than His love (pp. 73-4). He observes that the Qur'an speaks of God's mercy rather than His love, yet even so that mercy is "only one quality among many others which God displays in dealing with men, and which may, at times, be overshadowed by other qualities of might and power". This is contrasted with the portrayal of God's love in the New Testament as "something constant and unchangeable, the very nature of God himself" (p. 75). Geisler and Saleeb cite Qur'anic verses which emphasise God's mercy, compassion and forgiveness, but find that ultimately the relationship between God and humankind in the Qur'an "is described in terms of master (rabb) and slave ('abd). God id the sovereign Monarch who requires man to submit to him as an obedient slave" (p.27). Chapman, however, warns against understanding this servant-master relationship in terms of servility or degradation. ("Biblical Foundations of Praying for Muslims". p. 307) According to Brown, the God of the Qur'an resembles "a king exercising he prerogative of mercy", rather than "a father who suffers with his child and loves him out of his disgrace" (p. 75), while Glaser comments that "God's love may cause him to have mercy on his creatures, even to the extent of communicating with them; but it is a love that condescends in beneficence rather than a love that shares in relationship". ("The Concept if Relationship", p..58)
Some feel that the love of God as depicted in the Qur'an is conditional, since "the Qur'an always speaks of God's love for the righteous or the believers and never of his love for sinners". (Nazir-Ali, "Islam: A Christian Perspective", p.62) Chapman elaborates on this: while God loves "certain kinds of people". including those who do right, the God-fearing, the patient, and those who do battle for His cause, "God does not love certain other kinds of people: aggressors (2:190), the corrupt (5:64, 28:77), the evil unbelievers (2:276), the ungrateful (22:38)", etc. ("The God Who Reveals", p. 138) Moucarry contrasts the Qur'anic view with the biblical account in which "God loves all men equally, even those who disobey him, for his love is unconditional" (p.48)
God's relative "detachment" in Islam is attributed to various factors. While Christians stress the likeness between God and humankind as illustrated by the fact that God created man in His own image and then took on human form Himself at the Incarnation, Moucarry observes that Muslims, concerned to defend God's transcendence, conceive Him as "radically other" than humankind, even if not necessarily distant (p.47).
Some refer in this connection to the Islamic theological doctrines of mukhalafah ( difference) and tanzih (elimination of anthropomorphism), which maintain that attributes predicated of God do not have the same content when predicated of humankind. (N. Anderson, "Islam in the Modern World", p.25, and "God's Law and God's Love", pp. 101-2; Goldsmith, "Islam and Christian Witness", p.89)
This essential difference is often seen as entailing an ultimate agnosticism concerning the nature of God, since He is inscrutable both in His essence, which can never be known, and in the outworking of His will. (106) Geisler and Saleeb observe that the "ninety-nine names" of God preserved in Muslim tradition contain epithets that appear to contradict each other (e.g. "the One Who leads astray" and "the One Who guides"). Although this can be explained by reference to the fact that they describe God's will rather than His essence, nevertheless they are understood to mean that ultimately, as far as humans are concerned, God's actions are arbitrary: "the action of his will may be identified from its effects, but his will itself is inscrutable. From this it may be concluded that God is not necessarily loving, holy, and righteous in every situation" (p.26)
Another aspect of God's detachment is His impassibility, i.e. the belief that God cannot experience pain or suffering, or, more extremely, emotions. (107) Citing relevant texts from the Qur'an and Hadith, Glaser states that Muslims feel that "man cannot affect God", since this would detract from his power and self-sufficiency ... he cannot cause him grief or joy", and concludes that "although God has deigned-? to communicate with hid creatures, and even to love them, the relationship cannot be mutual since man's response can make no difference to God", and "the ultimate in relationship is willing submission rather than interaction." (108) Schlorff seems not even to acknowledge this one-way affection from God to the creature, and states more categorically that according to Muslims "God has no feelings or affections for any creature" (his italics). He is more in line with Muslim thinking when he continues: "Were God to display emotions, this would made Him like men and would be a weakness... He gains nothing from our obedience and loses nothing from our rebellion." (109)
According to Moucarry, "bowing before God's unfathomable and transcendent nature, Muslims say what God is. Receiving his love ... Christians confess who God is" (his italics, p. 49). The less personal conception of God in Islam is seen as being reflected in a lesser concern with God's character in the Qur'an than in the Bible. Geisler and Saleeb quote the eminent Muslim modernist scholar Fazlur Rahman, who claims that " the Qur'an lis no treatise about God and His nature: His existence, for the Qur'an, is strictly functional" (p. 19). They cite other Muslim authorities to demonstrate that "whereas in Christianity Christ is believed to be the self-disclosure of God, in Islam the emphasis if the Qur'an is not on revealing God per se, but more important, in disclosing the commands of God". Furthermore, "according to orthodox Islam, the purpose of man is not to know God and become more conformed to his character, but to understand his will and become more obedient to his commands" (pp. 101, 47).
Without exception, Christians view themselves as monotheists, and do not consider that the concept of plurality within unity in the Godhead in any way contradicts this. Various analogies are used to try and convey this to the Muslim; among those used by Geisler and Saleeb are that of a person's mind, thoughts and words which have a unity but are still plural, and, perhaps slightly provocatively, that of Muhammad, who is at one and the same time husband, prophet and leader (pp. 263, 269). By contrast, Islam's monotheism may be described as "rigid and inflexible"; Geisler and Saleeb believe that in its simple undifferentiated oneness it resembles a product of human reason rather than divine revelation (pp. 134-5). Moucarry also pursues the theme of the limitations of human reason; although he doesn't accept that the Qura'an itself is anti-trinitarian, since he believes that it rejects tritheism rather than trinitarianism (p. 82), he feels that later Muslim interpreters were, in the belief that "human reason ... is capable of grasping, by its own effort, the truth of its Creator. In the Christian view, this truth is inevitably too high above mankind to be grasped by our unaided reason. It therefore includes "mysteries" which the Scriptures reveal and which can be grasped only by faith" (p.91). Haddad feels that the simplicity of absolute unity is unbecoming to God: "the bare and solitary Oneness of God is easier to fathom than the nature of man himself ... If God is a rigid unity, then he is less than his creature" (p.58)
Some missionaries recruit philosophical arguments for plurality within the divine nature; these often echo the arguments which were used in the medieval Christian-Muslim theological debates. Moucarry asks: "how can the universe be recognised as having a real existence unless the principle of "otherness" within the Creator is acknowledged?", and feels that only a plural monotheism "permits a qualitative distinction between God and man, conferring on man a separate and real identity" (pp. 88-9). Abdul-Haqq develops this idea, maintaining that the denial of any multiplicity within God may lead to the view that all of creation lis "against the fundamental nature of God", and in this light the Quranic statement: "everything will perish save His countenance" (28:88) would mean that even heaven and hell will cease, leaving "no promise of life everlasting for the creature" (p. 183).