We have all done bad things, and these things not only offend others and harm ourselves but offend God, who created us and everything. We all - every single one of us, including Christians, who are not saved by anything they have done or any attribute but that of God's redeeming love - have sinned, which is what we call wrongdoing, against a holy God and deserve eternal punishment. It might seem extreme, but that is because of how incredibly holy God is and how important it is to follow His Laws. When anything goes wrong, or when your conscience goes off and tells you you have done something bad, it always affects your life and others' later down the line. It has an even greater effect, too, when it effects the world around you and pollutes creation. This is how we inherited Adam's original sin, which made us inherently sinful. There is no way to avoid being sinful, but we can avoid punishment and be made improved day by day - our wrongdoing can be paid for by Jesus Christ.
God came to earth 2000 years ago to pay for all our moral debts, wholly God, so that He would override original sin, yet wholly Man, that He would take our place and live a human life like us. He lived it all without sinning and died a horrible death of crucifixion, ironically accused of blasphemy. On the Cross, he suffered God's wrath - the wrath talked of in these Psalms and the wrath we deserve for our sins - and took our place, meaning that we are looked upon by God as if we have His righteousness, and He was looked upon in that moment as if He were us, filled with sin and worthless. God Himself, wounded and killed for us. But He triumphed over death: this is what His miracles foreshadowed, His Resurrection. On the third day, the Christ rose from the dead and appeared in Resurrected form to some of His disciples who have shared their testimonies in Scripture. He defeated death and hell for us, that we do not need to suffer. How is this just? Because God paid for us. God condemned us, but He also paid for us, like a good Father. We don't deserve it, and it can be baffling at times, but He is truly just. He paid for justice to still be served - it was served unto Jesus, so that we could go free! All we must do is trust in Him fully, turning from all we have done wrong and asking for God's forgiveness earnestly for those sins.
If you would like to know more details, consider reading the accounts of the gospels yourself in the Holy Bible. Then, go on to read Paul's epistles, and after that start to read the Old Testament, this time with new eyes and, Lord willing, a new heart.
My prayers are with you.
