“My behavior doesn’t matter?”

Is the Israel of today the same as the Israel in the Old Testament? Why does Jesus say you can’t pour new wine in old wineskins? Are we in the end times? I’ve heard people say, “My behavior doesn’t matter, because I’m saved no matter what!” What do you think about that?

“Do divorce and remarriage mean perpetual adultery?”

What’s wrong with mixing the old and new covenants? Do those who die young miss God’s blessing (of a long life)? I grew up Jewish. Now I’m a believer, and I wonder where my Jewish heritage fits in. Does Romans 7 say that divorced and remarried Christians are living in perpetual adultery?