There are words and phrases that mark every generation and culture. Some become so over-used that they grate on your nerves. In our present generation we constantly hear people saying, "It's all good." My first response (in my head of course) is, "No, it's not!" There is evil in the world. There are things that are good, and things that are bad. There is such a thing as sin. It is not all good.
The sad truth is that if you listen to the tone of voice with which some people say, "It's all good", what you will hear is "I don't care" or "It doesn't bother me", an attempt at emotional detachment, and attempt at avoiding pain.
But as a Christian there is a healthy understanding of the phrase. If we use it as a paraphrase of St. Paul's letter to the Romans.
for those who love God all things work together for good ( panta synergei eis agthon).
The key to this passage is the word synergei from which we get the word synergy. The difference is that we are not saying that each individual things is good. We know that some things are bad, some are evil. The child being shot at the McDonald's in my parish was evil, mortal sin. What St. Paul is telling us is not that the individual pieces are all good, but that God can take even the most horrible thing in the world and put it together with his grace so that the sum total, the panta is in fact Good. -the Divine Synergy.
Someone insults you. Let it go. God will counter balance it. My brother was killed in a car accident when he was 17 and I was 12. I thought it was the end of the world. Four years later God sent Harold (who I just was visiting in Costa Rica) and I not only had a new brother but a whole second family to love me until Michael and I are back together in heaven.
Even when we are the ones who are responsible for wrecking our own life, God can take that and turn it to the good, if we hold on to our faith. Remember the verse does start off "for those who love God." Actually the verse starts off with another more important word oidamen "we know". St Paul doesn't claim that this is something that we believe; it is something we know.
Notice this is not karma. Nowhere does St. Paul tell us that God will repay evil with evil. As a matter of fact in the same Letter to the Romans we are commanded
Do not repay anyone evil for evil. Be careful to do what is right in the eyes of everyone.
And in First Peter we hear:
Do not repay evil with evil or insult with insult. On the contrary, repay evil with blessing, because to this you were called so that you may inherit a blessing.
If I know that for every bad word spoken to me or about me, every bad thing that happens to me, in the Divine Synergy, God is going to make it work out to the good then who can possibly rob me of my peace? Why do I need to get angry or upset? There is only one thing I need to do, Remain always among those who love God .