In the first verse it starts out with the word "but." In the previous chapters we had seen how the church was working together and sharing all they had with each other. But when Ananias and Sapphira are mentioned the mood of the book changes. They not acting like the rest of the church. They had wanted to be apart of the community when it came to giving in front of others but they still wanted some for themselves. When Ananias was in front of Peter, he knew somehow that the couple was lying. They had said they had given all but had really only given a part. The sin wasn't that they withheld some of the money but that they lied about it. No one knows why God decided to judge the man instantly but it sure shook up the people in the community. After dropping dead it wasn't much longer that Ananias wife Sapphira after being questioned the same as her husband also dropped dead. Even though she was being loyal to her husband to follow him she still was acting in sin against the Holy Spirit.
Because of the things that the apostles were doing many people admired them but didn't spend time with them personally. I imagine that it was a little had to be around people who were so on fire for the Lord and you weren't doing the same things as them. The people had such admiration for Peter that they would even put sticks in the road hoping that his shadow would be cast on it and heal people. No where in scripture does it say that his shadow actually healed.
The leaders of the main groups didn't like what they were hearing the disciples do among the people. So they quickly had all twelve arrested probably fast so word wouldn't spread. But that night an angel appeared to them and after telling them to go and preach he released them. The doors were never opened and the guards never knew that they had left. After finding out where they were the leaders had them called back in order to question them. They told the disciples again that they were not to preach an the name of Jesus but all twelve of them agreed that they were to serve the Lord first before man. The leaders didn't like this at all and if it weren't for the Pharisee named Gamaliel they probably all would have been killed right then. Gamaliel figured that if the movement wasn't anything big it would die off eventually and if it was something from God then he didn't want to receive wrath from God for it. The disciples were told once again not to preach anymore and then were beaten before getting released. The disciples didn't mind the beating because it meant they had suffered for the Lord. As to be expected they continued to preach everyday at the temple. How often are we willing to suffer for Jesus because of our actions. Too many times we let our lives get too comfortable.