The apostles taught them many things (Acts 2:42), but one reaction to their newly found salvation in God's new Savior was spontaneous. Generosity exploded!

"Then fear came upon every soul, and many wonders and signs were done through the apostles. Now all who believed were together, and had all things in common, and sold their possessions and goods, and divided them among all, as anyone had need. So continuing daily with one accord in the temple, and breaking bread from house to house, they ate their food with gladness and simplicity of heart, praising God and having favor with all the people. And the Lord added to the church daily those who were being saved." (Acts 2:43-47)

"Now the multitude of those who believed were of one heart and one soul; neither did anyone say that any of the things he possessed was his own, but they had all things in common. And with great power the apostles gave witness to the resurrection of the Lord Jesus. And great grace was upon them all. Nor was there anyone among them who lacked; for all who were possessors of lands or houses sold them, and brought the proceeds of the things that were sold, and laid them at the apostles' feet; and they distributed to each as anyone had need. And Joses, who was also named Barnabas by the apostles (which is translated Son of Encouragement), a Levite of the country of Cyprus, having land, sold it, and brought the money and laid it at the apostles' feet." (Acts 4:32-37)