Fitnah & Fassad facing Muslims in the West

As-salam alaikum,
As far as I'm concerned from my personal experience, this is one of the greatest threats to Islam surviving in these Isles. (Despite my Muslim identity being shielded like an onion by multiple layers e.g. claimed Quraishi blood, claimed multiple Islamic ethnic mixtures which propagated Islam & kept it firm for centuries in an assimilating pagan land outnumbered & attacked regularly so espirit d'corps, strong racial/religious difference to majority & self-confident educated leonine father who fought, defeated & won the hearts of racist White Britons & Ashiq-e-Rasul (sallalahu alaihi was-salam) & loving, honest, simple Iman beautiful in looks & spirit mother (masha'Allah), personal possession of thousands of books, eclectic love of knowledge, ribat-like stance on refuting polemics inspired by Shaikh Ahmed Deedat, & comprehending the absolute NECESSITY of Dawah to the non-Muslim majority & transmission of a non-degraded sharpening Iman to the future, our children).

WHY the tilting towards ATHEISM, despite being aware of its ancient existence even among the defeated cynical wordly Quraish?

1- ASSIMILATION of the majority tribe's deen, despite being aware that little Shaitan is glaring at me from my childhood! The "rational" beginning is that nothing is given credence UNLESS it proves itself, despite being aware of my finite life & capabilities e.g. whole of Mankind for centuries could NOT prove 1+1=2 until the early part of the Christian Gregorian C20th.
Islam has to justify itself as the strongest horse.
What are the pillars for me on what Islam stands? Allah (subhanu wa ta'Ala)= YES. Muhammad (sallalahu alaihi was-salam's) integrity (honesty, decency), message & prophetic abilities = YES, Quran-sharif's divine origin, miracle & message = from unproven moving to something inexplicably there, but almost ephemeral , intangible & personal power, BUT cannot rationally convince a non-Muslim atheist rationalist as a daiee. I'm not a speaker of Hijazi Arabic, though I understand that Christian Arabs can feel overwhelmed. The proof of the pudding where the root produces good fruits = MIXED, the behaviour of some good Muslim taxi drivers in contrast to the daggers drawn vicious blood thirsty attacks of Uncles & aunties once my shield father had passed.

For other's polemics like claimed paedophilia have cut them from the roots as they have assimilated the transient capricious values of the majority tribe in toto.

The acidic sectarian infighting has loosened the bonds of friendship, unravelling the rope of the Ummah. Tribalism & Identity politics.

However, if at the heart, one is not convinced 99.999% that the kalima shahadat is CERTAIN, then unlike when you avoid traffic on a road, it is just not real but opium of the people, inherited fables of the ancients. As racial-religious mixing loosens the bonds of kinship further, even aalims not defending the rock of marriage betwixt male & female under pressure from authorities & local nation-state Islams fragment Soviet style, Shaitan will cash in on the gamble as the children of poor dark Muslims swap eternal wealth for the transient fool's gold.
He attacks from in front & behind, above & below, left & right, inside & outside.