While Islam and Christianity are similar in many aspects, there two fundamental differences between both religions. These fundamental differences are practically impossible to breach, because they lie at the very core of what defines each religion. However, in practice, the values, ethics, and morals of Islam and Christianity are almost identical. To understand how both religions can strive to find common ground, it is first important to understand the nature of the fundamental disagreements between Muslims and Christians.
The most important difference between Islam and Christianity lies in their very concept of God. Both religions worship the same God, the One True God, the Creator of everything, the Source of everything, the One that knows all, omnipotent, and has eternal compassion for His creation. A God that is fundamentally Just and that loves His creation. However, Muslims and Jews ascribe absolutely no partners or associated to God. Christians believe that Jesus, the Holy Spirit, and the Father form a Trinity, a concept that is rejected absolutely by Muslims. However, Muslims believe that Jesus was one of God's messengers to mankind and he holds an exalted place in the Islamic faith. The second fundamental disagreement between both religions is that Christianity believes that Jesus was sacrificed for mankind's sins. Muslims believe that the relationship between Man and God is individual, and that there can be no intermediaries between God and Man. Muslims believe that sacrifice does not atone for sins; Muslims believe that the only way to atone for a sin is to repent completely and to attempt to correct the consequences of one's actions.
There is no question that the disagreements on the Trinity and of the Christian concept of the atonement of sins cannot be resolved between both religions. However, both religions stress the importance of love, doing good deeds, and having faith in God. Practically speaking, one finds that good Christians and good Muslims have the same core values and live their daily lives in the same way. It would be impossible to distinguish one from the other by their core values. Piety in both religions involves submitting to God's will, praying, giving to charity, and loving one's neighbor. While Muslims place a greater emphasis on living a virtuous life and showing one's love of God by doing good deeds, there is no question that Muslims believe good deeds are useless if there is no faith in the One, True God. Christians place a greater emphasis and loving and believing in the same God as Muslims, but no Christian would deny that a requisite of loving God involves showing it through one's deeds. One does not offend or hurt those that one loves.
-- Al Arabiya Digital