1 Peter 3:11 - Matthew Poole's English Annotations on the Holy Bible

Let him eschew evil, and do good; let him not only in general avoid all sin, and exercise himself in all well-doing, (as the prophet's meaning, cited in the margin, seems to be), but particularly, let him avoid all sin against his neighbour, not recompensing evil to him, and doing him all the good he can, and overcoming evil with good; and to this the apostle accommodates the prophet's words. Let him seek peace; not only with God and his own conscience, but with his neighbours, which is here especially meant. And ensue it: either seeking and ensuing signify the same thing, viz. an earnest desire of peace, and use of all lawful means to obtain it; or, ensuing it may signify the difficulty of obtaining it; when we seek it, it may seem to fly from us, men may not let us have peace when we would have peace, Psalms 120:7, and therefore we must follow it, Hebrews 12:14.