LIKE vs. AS

Like means "same form, appearance, kind, character" and is followed by a noun or noun phrase.

As means "in the manner" and is followed by a clause (subj + verb).

My brother is like me.  (prep.)                                    My brother thinks as I do (I think). (conj.)
He's smart like a fox.  (prep.)                                    He is as smart as a fox .  (idiom)
He's more like forty plus.  (adv)                                 He writes as a man in his forties writes.  (conj.)

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