Um, this is not ancient Israel, Tiffany. This is the modern United States of America.
Okay, now we've established where we are geographically and historically. It's time to ground yourself intellectually as well.
"Undocumented" is illegal. These people have not gone through the proper process to enter and be assimilated into our society. They need to stay in their own and improve it, or else follow the rules already laid down for becoming part of ours. Circumventing that is illegal and immoral as well. We are under no Biblical injunction to aid lawbreaking, especially for such reasons. Our country gives untold billions in foreign aid to every country imaginable, including Mexico. We are not lacking in compassion by insisting they follow our laws.
It took 16 years for us to finalize the American citizenship of our daughter whom we adopted while living in Brazil in the late 80s. 16 years! While "undocumented"--I mean, illegal--aliens were running roughshod over the very generous system set up in this country to help our own people in need, and while Arab terrorists were entering on student and visitors' visas to murder and maim.
Your ill-advised clamor for open borders is all emotion and demonstrates an obvious lack of considering the consequences. But then, liberals are famous for acting upon emotion and impulse, and leaving conservatives to clean up the mess.