Montalban said:
I'm interested in what you got out of Islam.
And, to see if you couldn't have got that out of Christianity
In other words, what is Christianity lacking?
I would not say that Christianity lacks anything, so in a strict sense there is no need for a Christian to turn to another religion for anything that is lacking in the Christian faith.
Having said that, I believe that those who can do so have the Christian freedom to study, enjoy, and even benefit from another religion; and it it is my belief along with such writers as Griffiths, Schuon, Merton, and others that it is possible for certain religious studies to enhance Christian experience and awareness.
Speaking specifically about Islam, I am impressed by its unequivocal view of Allah's sovereignty to the extent that it is the pronounced goal of a Muslim not only to accept trials as coming from God, but also to be content in the midst of those trials since, after all, they are an expression of God's will.
Although there is no shortage of piety in Christian saints, I am nevertheless inspired by the piety of Muslim saints. As I mentioned elsewhere, I found inspiration in some of the stories about Rabia, a Muslim woman who reportedly prayed,
Lord, if I want you for your Paradise,
please deny me Paradise;
if I want you in order to avoid Hell,
then please send me to Hell.
But if I want you for yourself alone,
please don't deny me your bounties.
Another thing I enjoy about Islam is the Arab genius for statements such as in 50:16 of the Quran: "God is closer to man than his own jugular vein." There is an explicit, visceral statement of God's imminence that gets the point across with an image that stays in one's mind.
These are three examples only. There are also the Islamic mystical concepts of fana (the passing away of the self into God) and baqa (subsistence in God), in addition to the Islamic concept of the remembrance of God and the practice of dikhr. ("Remember me and I will remember you." Quran 2:152.)