How do you rationalize cherry picking the parts of the old testament you like and ignoring the rest? [Spirituality & Religion]

Don't forget killing disobedient children and slavery being a natural human condition. I love shooting them down from their 'holier than thou' pedestal by reminding them that they're not even true to their religion themselves. If you believe your God is infallible then you can't pick and choose which rules to follow. Either all of it's okay or none of it's okay.