who was abraham

i dont understand about abraham. for example, why is he our father of faith. did we all come from abraham? and abraham was a jew then? im looking for background information on who he was and why he changed his name to abraham and to sarah. oh and was abraham rich? because he wanted a son to inherit his estate, yet he thought some other people would, so is having an estate mean that he was rich? and because abraham didnt follow god completely by going his own way and having a son with thier maidservant, were there consequences?

There is a series here which will give you a start in your enquiries...

[url=https://www.sermonindex.net/modules/newbb/viewtopic.php?viewmode=flat&order=0&topic_id=2034&forum=45&post_id=&refresh=Go]Abraham, my Friend.[/url]