What does Matthew 19:27 mean?

Peter is infamous for saying and doing exactly what comes to his mind, in that instant, for good or bad. That's a blessing to modern believers. Often, Peter blurts out honest things which we, too, might have said. In this case, he once again misunderstands Jesus' meaning about the difficulty of the rich being saved (Matthew 19:23–24). Peter remembered what Jesus had told the rich young ruler (Matthew 19:21–22) and wanted to know how it applied to him and the other disciples.

When Christ told the rich man to give up his money, he did it to prove that the man lacked real sincerity. Even this action would not have made the young man truly good, because only God is good. But Jesus was showing the man just how far from good he was; he would be unwilling to follow if God's will contradicted his will.

Peter, though, heard Jesus mention a condition and a promise. He and the other disciples had already lived up to the condition, by walking away from their previous lives. They did not likely start out wealthy, but they had left everything to follow Jesus. Jesus had told the young man that he would have treasure in heaven. Peter wanted to know if he and the disciples could expect treasure in heaven.