Teaching your children the truth as you know it, and insisting to them that all other perspectives are categorically wrong, are two very different things. Every child grows up speaking the language of his/her parents, or whomever is raising them. That doesn't require that they be told other languages are bad or wrong, to be avoided rather than studied. If parents don't provide spiritual guidance to children, even if it is to explain how they think spiritual beliefs are unnecessary, this leaves a vacuum for other people to fill as the child grows up.
The part about spiritual truth being subjective.
It doesn't seem this is true for everyone. Faith allows one to believe in something with impunity even if that belief is shown to be wrong compared to the facts of reality. I'd agree with this claim that we'd change our minds if we've arrived to our previous beliefs by way of reason and evidence and not faith or indoctrination.
If something can be disproved (falsified), it is not a matter of faith but rather of scientific or historical fact. Faith is acceptance of something that cannot be proven.
Your comment about the Trinity not making logical sense made me chuckle. If God is really an all-knowing supreme being, would you really expect human minds to be capable of fully understanding such an entity? Herein lies the problem that most people have with faith, they can't accept that anything could be more intelligent or capable than man-- this of course makes no sense in light of the concept of deity.
The trinity makes no more or less sense than any other construct humans use to try to relate to the transcendent, infinite entity that is Deity. IME, why limit it to three? Even the various pantheons of Hindu, Native American, and pre-Christian traditions can be viewed as simply aspects of a single divine entity, though not all believers see them this way.
Why not? I love Jesus. He is my prophet. One of them. One of the greatest. And only Islam mentions Jesus, not Hinduism, not Buddhism or Judaism.
Bahai faith honors Jesus, and Muhammad, and Abraham. As expressed in their doctrine of progressive revelation, all the divine prophets came to reveal the same truth to humanity, in different ways suitable to the different times and circumstances. And the Bahai's are persecuted in Shiite Iran.
That said, your claim that Christian Faith and Islam are more simmilar than not, is false from a Christian perspective. You seem to not quite understand some of the theology: Christ said that no one comes to the Father, except through him-- through the law-breaking grace that he gave us by making a sinless sacrifice of himself. This is the main difference between Islam and Christ: in Christ I have grace from a loving God, so I don't have to be perfect (which I couldn't achieve anyway)! Good fruit and a desire to live a loving, God-honoring life comes naturally out of that freedom-- which is totally different than seeking to measure up, strive or attain perfection based on a legal structure (of sin). Christ defeated sin's power over us, and all we need do is claim that-- that's why, in Christianity, there is no "worst sin" because my God is bigger than any mess we humans could find ourselves in. Islam and Judaism are still slaves to sin, with no way to sustainably atone for it. And let's be real, you sin, I sin, we all are guilty of sin. Christ just provided an eternal solution. The Christian God sacrificed his own son for his people, Allah expects you to earn your own way (even though no one can ever attain perfection enough, to be in the presence of a holy God).
So bottom line: my God and your God have very different character traits, and we have totally different ideas about how one deals with the sin problem.
Actually, "your God" and "Mustafa's God" have many commonalities as well, perhaps because they really are the same God (perhaps because there really is only one?) Have you read anything by Joseph Campbell? He does a good job of showing the common threads among all the world's religions. And no, that isn't justification to merge them all into one holy mess, any more than we should all adopt a common language, cuisine, or style of dress. There are many paths up to the mountain top. Put another way, God never stops reaching out to people, to bring them closer to him.
There's also no scriptural basis of comparison as to how husbands and wives should behave, while wives should submit to their husbands, husbands are instructed to be gentle and loving to their wives, giving her no cause to hate him. In Islam race isn't an issue, but they still make a huge difference between men and women, while in Christianity while there's also no difference between "Jew nor Greek, slave nor free, MALE NOR FEMALE"...there's no scriptural grounds for beating or demeaning women or treatment of women as second class citizens after the gospels of Christ.
There is no difference between male or female, until there is. One of the many contradictions in the Bible. At best, the Bible offers a kinder, gentler sexism.