Edited in light of Matt’s comment below – 

1A. 18 Servants, be subject to your masters with all fear; not only to the good and gentle, but also to the froward.

1B. 19 For this is thank worthy (charis),

1C. if a man for conscience toward God endure grief, suffering wrongfully.

1D. 20 For what glory is it, if, when ye be buffeted for your faults, ye shall take it patiently?

1C’. but if, when ye do well, and suffer for it, ye take it patiently,

1B’. this is acceptable (charis)  with God.

1A’. For even hereunto were ye called:

2A. because Christ also suffered for us,

2B. leaving us an example, that ye should follow his steps:

2C. 22 Who did no sin,

2D. neither was guile found in his mouth:

2E. 23 Who, when he was reviled, reviled not again;

2E’. when he suffered, he threatened not;

2D’. but committed himself to him that judgeth righteously:

2C’. 24 Who his own self bare our sins in his own body on the tree,

2B’. that we, being dead to sins, should live unto righteousness:

2A’. by whose stripes ye were healed.

3A. 25 For ye were as sheep

3B. going astray;

3B’. but are now returned

3A’. unto the Shepherd and Bishop of your souls.