"See that no one repays anyone evil for evil, but always seek to do good to one another and to everyone." -1 Thessalonians 5:15Author John Grisham (from our neck of the woods, incidentally) wrote "A Time To Kill"; still one of my favorite novels. The plot revolves around attorney 'Jake Brigance' and his defendant, an African-American father, in Canton, MS. The defendant was on trial for the court-room murder of the very man who had killed his 10 year old daughter. The story-line is rivetting to be sure! Imagine, especially if you are a father or mother, the emotion that would course through your veins ...if it were you or I in this scenario. "...life for life, eye for eye, tooth for tooth....." We would most likely agree with the Exodus passage!!
Yet, this idea, this very statement, seems to run opposite of what the Apostle Paul stated to the church at Thessalonica. (1 Thess. 5:15)
Was the concept of "eye for an eye" acceptable in the old covenant / agreement with God ...and not acceptable in the new covenant? Is this, as scoffers would say, evidence that Scripture contradicts itself? As a slight "side-bar", allow me to say that.... I admit it! I thoroughly enjoy wrestling these, seemingly, difficult passages, and concepts, in God's word. I do believe the original text penned by those whom God inspired are, indeed, the words of God Himself. Allowing scripture to interpret itself reveals, not only, that there are no contradictions ...but the seamlessness of the message from the multiple authors, across multiple time-lines, with many different circumstances and biases ...only compounds the validity of the claim of holy scripture being inspired by God ...through man, and in spite of him.
Back to the question at hand... "do the aforementioned passages reveal a contradiction in scripture?" We should look to the object, and instigator, of this supposed contradiction for the resolution. The gospel according to Matthew records Jesus' own words... ""You have heard that it was said, 'An eye for an eye and a tooth for a tooth.' 39.But I say to you, Do not resist the one who is evil. But if anyone slaps you on the right cheek, turn to him the other also. 40.And if anyone would sue you and take your tunic, let him have your cloak as well. 41.And if anyone forces you to go one mile, go with him two miles. 42. Give to the one who begs from you, and do not refuse the one who would borrow from you." -Matt. 5:38-42 (ESV)
Our righteous, sin-less, all-powerful God demands justice! Our loving, sin-absorbing, omni-present Savior provides mercy and grace! It is no contradiction to follow the teaching of the Christ, by whom the law, and justice, exists, and by whom it was, once and for all, "fulfilled" -Matt. 5:17 (ESV)