Prayer and Study can (and should) be done both in private and publicly as part of a group. Learning in a class and praying at church with others is the Jesus way. Praying alone and studying is also the Jesus way. Is there more to being a disciple than that?
Ministry, mission, apostolic action, work-- all these are terms used to refer the fruit of our life. I choose the term "Kingdom ethic" because I hope it will keep us out of the morass of "faith vs. works" which seems to muddy up so many discussions. I am not real interested in those battles. I want to live and love and serve! (well, most of the time....)
Jesus offers us entrance into a new mode of existence. It is called citizenship in the Kingdom of God. In the Kingdom, God is the King and Ruler. He decides the expectations and He judges each person. Jews are the original members of this people. However, there has always been some place for Gentiles. In the OT this was usually vague and uncertain. In places there seems to be no room for us, while other times the invitation is quite open. Since Jesus, that invitation is much clearer. Paul writes about it quite a bit. You and I have become fellow citizens. (Other images include being grafted into the vine, being adopted, becoming part of the body of Christ) In God's Kingdom there are some serious expectations. Some of the major themes include the command to worship no-one else except God, to live justly and look after the needs of others and to live pure lives which are moral and merciful.
We are brought into the Kingdom by God's grace, it is not earned. There is nothing we have done to warrant it (just like God makes clear that it His choice of the Jews was pure grace). God has also chosen us and offered us this life and expects us to trust (faith) Him and to love Him. Once we are in the Kingdom (baptism is our citizenship ritual) there is a mode of life expected of us as citizens. There is an ethic ("way to walk" in the Bible) which we are called to embrace. So what we do matters. Faith has an intellectual content, a volitional content, and an emotional content, but it also has a moral-behavioral content. In the city of God we just do not do certain things. In teh Kingdom of God we are expected to do certain things. People who are not comfortable living the way the Father/King expects are not going to stay in the Kingdom. In the end, we will not live forever in peace and joy and harmony, we won't be able to love and worship God, if people continue to act the same way they do now. Something has to change and that something is our hearts and our behaviors. A "rule of life" addresses that needed change. The Kingdom ethic is our next focus.