All 3 Uses of

therefore
in
Oliver Twist

Mr. Sowerberry rightly construed this, as an acquiescence in his proposition; it was speedily determined, therefore, that Oliver should be at once initiated into the mysteries of the trade; and, with this view, that he should accompany his master on the very next occasion of his services being required.†
Chpt 5 *

therefore = for that reason

It was quite obvious, therefore, that it was the gate; especially as there was no doubt regarding the time at which the change had taken place, because all three remembered that they had come in sight of the robbers at the instant of its occurance.†
Chpt 28

The suspicious circumstances, however, resolving themselves, on investigation, into the one fact, that they had been discovered sleeping under a haystack; which, although a great crime, is only punishable by imprisonment, and is, in the merciful eye of the English law, and its comprehensive love of all the King's subjects, held to be no satisfactory proof, in the absence of all other evidence, that the sleeper, or sleepers, have committed burglary accompanied with violence, and have therefore rendered themselves liable to the punishment of death; Messrs. Blathers and Duff came back again, as wise as they went.†
Chpt 31

Definition:

for that reason (what follows is so because of what was just said)