Islam means "submission", and Hirsi Ali's experience of Islam was one marked by submission in many aspects of life. In the first place, this submission refers to the relation of the individual Muslim to Allah.
In Islam, unlike in Christianity and Judaism, the relationship of the individual to God is one of total submission, slave to master. To Muslims, worship of God means total obedience to Allah's rules and total abstinence from the thoughts and deeds that He has declared forbidden in the Quran. (p. 313)
"Unlike in Christianity"? No way - the God of the Bible also requires no less than total submission and total obedience:
Submit yourselves, then, to God. Resist the devil, and he will flee from you. (James 4:7)
Do not be stiff-necked, as your fathers were; submit to the LORD. Come to the sanctuary, which he has consecrated forever. Serve the LORD your God, so that his fierce anger will turn away from you. (2 Chronicles 30:8)
You must obey my laws and be careful to follow my decrees. I am the LORD your God. (Leviticus 18:4)
But now that you have been set free from sin and have become slaves to God, the benefit you reap leads to holiness, and the result is eternal life. (Romans 6:22)
The relationship between God and the individual is indeed one of master and slave. So what's the difference? It is at the same time a relationship of mutual love, even between a Father and His children.
Now if you obey me fully and keep my covenant, then out of all nations you will be my treasured possession. (Exodus 19:5)
Love the LORD your God and keep his requirements, his decrees, his laws and his commands always. (Deuteronomy 11:1)
The LORD your God is with you, he is mighty to save. He will take great delight in you, he will quiet you with his love, he will rejoice over you with singing. (Zephaniah 3:17)
If you, then, though you are evil, know how to give good gifts to your children, how much more will your Father in heaven give good gifts to those who ask him! (Matthew 7:11)
This, then, is how you should pray: 'Our Father in heaven...' (Matthew 6:9)
How is this possible? Jesus says:
I tell you the truth, everyone who sins is a slave to sin. (John 8:34)
One is either a slave to sin, or a slave to God. God's slaves have to keep his entire law. But no mere man can:
There is no one righteous, not even one. (Romans 3:10)
Who could fully submit to and obey the laws of the almighty God in our place? And who could pay the penalty for our sins and earn his love for us? Jesus Christ, the Son of God born as man:
For we do not have a high priest who is unable to sympathize with our weaknesses, but we have one who has been tempted in every way, just as we are—yet was without sin. (Hebrews 4:15)
For I have come down from heaven not to do my will but to do the will of him who sent me. (John 6:38)
But we see Jesus, who was made a little lower than the angels, now crowned with glory and honor because he suffered death, so that by the grace of God he might taste death for everyone. (Hebrews 2:9)
For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.
So there is no tension between an almighty, holy, demanding God, and a loving, forgiving, and merciful Father. And there is no tension between loving and serving Him.