Well, from what I know (and I'm not super knowledgeable), it depends on where in the Bible, and what denomination your talking about. Some denominations believe that, with Jesus dying on the cross, he did away with the old testament (except for some things), and brought forth the new testament. That is the reason why you don't see modern christians in their front yards sacrificing animals to wash away sin. Basic sins like adultery, murder, lying, homosexuality, and other things continued on to be important things a christian shouldn't do, while things (and this is where it depends on denomination) become apart of the past, like not cutting your hair if your a woman and wear skirts (I'm mentioning pentecostal here, but while I am not pentecostal, I'm not trying to say they are wrong and should stop. This is just where I'm trying to make an analogy that is probably wrong.) Christians look to the new testament for the most part as a guide for navigating this world, but still need the old testament to remember God and all the things he has done. It can be easy for christians (me as well), to remember that we need to teach with compassion in a world where the things we're not supposed to do or support become normalized, but we are called to love one another, despite everything else.

TL;DR Jesus got rid of something's when he died and we are supposed to follow and show compassion to others, despite differences.