What is Benjamin saying in thesis VI in On the Concept of History?
I quote it in full from here, having annotated the key points I'm struggling with in bold
To articulate what is past does not mean to recognize “how it really was.” It means to take control of a memory, as it flashes in a moment of danger [what does this mean?]. For historical materialism it is a question of holding fast to a picture of the past [to how it really was?], just as if it had unexpectedly thrust itself, in a moment of danger, on the historical subject. The danger threatens the stock of tradition [the dead?] as much as its recipients. For both it is one and the same: handing itself over as the tool of the ruling classes. In every epoch, the attempt must be made to deliver tradition anew from the conformism which is on the point of overwhelming it [is this an argument and if so how can it be paraphrased?]. For the Messiah [the rest of this thesis is beyond me] arrives not merely as the Redeemer; he also arrives as the vanquisher of the Anti-christ. The only writer of history with the gift of setting alight the sparks of hope in the past, is the one who is convinced of this: that not even the dead will be safe from the enemy, if he is victorious. And this enemy has not ceased to be victorious.
To be specific, I'm confused as to why he appears to be defending a messianic version of historical materialism, when thesis 1 seems to say that
historical materialism is actually a quasi-religious fraud