The fact your own bible states god is a mass murdering, baby killer that supports slavery and all that is evil is bashing when its in your bible?
That's not bashing, it's stating biblical facts.
Disclaimer biblical facts have nothing to do with actual facts that can be demonstrated to be true.
The actual events you are referring to are old testament...hebrew texts.
They have for the most part proven to be a reliable history of the jews and the struggles that they encountered as they worked their way north from the sinai pennisula to the crossing of the jordan river near the city of Jerhico.
According to the bible God told the Israelites to utterly destroy these cultures as they moved thru the area to the lands that were promised to them earlier.
The reasons given are due to the people of the land living wild promiscuous lives...idol worship and the worship of false gods in addition to human sacrifice (typically children)
The reasoning as to why kill everyone is clear. That their would be no remaining opposition or future repercussions as the children grew up and sought revenge. Much like kids in the middle east today being trained to retaliate for the deaths of their parents..relatives etc.
There is also the doctrine that these children that have not yet reached an age of reasoning would therefore be allowed access to heaven and the presence of God.
The Jews themselves were subjected to the same fate at least twice...when Nebucanezer of Babylon destroyed Jerusalem in 700ish BC and killed nearly everyone and carried the rest off to become slaves in modern day Iraq...Then again in 70AD when Rome laid siege to Jerusalem destroying the temple and killing everyone in sight.
Both were due to the people living lives contrary to the commands of God according to the Bible.
But God also gave them and the earlier peoples time to change their ways and many warnings in many ways.
A classic example is the story of Jonah...not the belly of the fish part but the reason Jonah attempted to run from God was that God had ordered him to go to Ninevah...north east Iraq and walk thru the city announcing that God was unhappy with the people (Assyrians)and their lifestyle as a whole. If they would not repent and ask for his forgiveness then God would destroy them.
Jonah eventually did just this and the King of Assyeria( who happened to be a very well educated guy that could read and understand even the sumerian cunneiform texts that were already thousands of years old...this is according to archeological finds at the kings library in Ninevah) the king then commanded his people to repent and the city was spared for generations.
So the old testament and judaism both teach that God will give ample time to repent of behavior prior to punishment.
Christianity is different than the old testament and the teachings of judaism.
John the Baptist who foreshadowed the ministry of Jesus and Christs own message was one of repentance for falling short in day to day life individually.
The grace of God was extended to all that believed in the gospel of Christ and in his death and ressurection.
Op...this is just to clarify what is actually taught by the bible....not what is necessarily exhibited by the followers of jesus.
You had a bad experience with a very close minded professing christian...not all are wired that way.
The fact that christians in the name of christianity have carried out many of the most horrific events in human history doesnt negate the true message of the gospel as recorded in the bible.
It does however show you how sick and evil human beings can be.