When the crowds came to John for baptism, he said, “You brood of snakes! Who warned you to flee God’s coming wrath? Prove by the way you live that you have repented of your sins and turned to God. Don’t just say to each other, ‘We’re safe, for we are descendants of Abraham.’ That means nothing, for I tell you, God can create children of Abraham from these very stones.
The priests of the day were the ones Jesus would warn believers of. They were more worried about their status and being “religious” than truly following God. It’s the same thing as going to church and speaking Christianese, when your heart is not fully sold out for Christ. So the same warning stands today; you can’t fool your way into heaven. Your heart must be transformed, you must repent, you must believe that Jesus lived and died for your sins, and you will be humbled.