From the beginning, Magwitch is presented sympathetically. Even when he threatens Pip in the graveyard, it is more comical than frightening (to the reader at least).
Although Pip first describes Magwitch as a fearful man, the description of him is anything but intimidating. Although he “glared and growled,” his teeth also chattered.
A man who had been soaked in water, and smothered in mud, and lamed by stones, and cut by flints, and stung by nettles, and torn by briars ... (Chapter I, p. 4)
Pip goes to get food for Magwitch, but not just because he is afraid Magwitch will come after him if he doesn’t. He warns the convict that he could be hurt or sickened in the marshes. When the soldiers come to look for Magwitch, Pip is afraid for him. This is clear from the way he describes how the convicts are treated.
Water was splashing, and mud was flying, and oaths were being sworn, and blows were being struck, when some more men went down into the ditch to help the sergeant, and dragged out, separately, my convict and the other one. (Chapter V, p. 26)
When the reader learns that Magwitch is Pip’s true benefactor, we are surprised. However, Magwitch’s actions are always honorable. We learn that he has been wronged by Compeyson. We also learn that he wanted to make Pip a gentleman to prove that anyone can be a gentleman.
[This] is the gentleman what I made! The real genuine One! (Chapter XL, p. 223)
In the end, we see a better side of Pip through his relationship with Magwitch. Magwitch is his second father, and after he gets over the shock that Miss Havisham is not his benefactor, he treats Magwitch honorably and comes to care about him.
Magwitch returns to Pip’s life at a time when he is not the best person, when he has forgotten his roots. Although his experience trying to help Magwitch flee is a difficult one, it makes Pip a better person.