2nd:

thou shalt give life for life, eye for eye, tooth for tooth, hand for hand, foot for foot, burning for burning, wound for wound, stripe for stripe. -Exodus 21:23-25
... resist not evil; but whosoever shall smite thee on thy right cheek, turn to him the other also. -Matthew 5:39 (this is the classic contradiction between new and old testament)

you say this is a classic one, well let's get an understanding:

Exd. 21, is dealing with Laws to govern the people, given to Moses by God, notice who is given these laws GOD! what Christ is saying in Mat.5:39 is let God excecute the judgement of people who wrong you. If a person has wrong you not necessary turning the other cheek, but get away from that person. It's all about doing just judgement! So in Exd. GOD commanded how Israel should judge the people (the nation of Israel). It wasnt given to justify revenge but as a rule for personal relationships among the people. And all are just laws. Read the chapter again. Christ was just saying, let GOD do the judgement to those that harm you. It was a need to say this because every man had leaned toward what "they" understood about matters and not what God had to say (just like today)

the world laws are taken from the Bible. If you steal, kill you go to jail, if you cheat on your wife/husband there's consequences etc.. no different, Christ again, is saying let GOD judge the individual(s)