Who are the real Muslims?
There are people who have Muslim names but rarely, if at all, practice Islam. Others may attend to certain Islamic practices on occasions, such as those who offer their prayers only on Fridays, and perhaps in Ramadhan when they do fast. Please comment.
There should be a practical interpretation of beliefs. Otherwise, it will remain theoretical. Hence, the Prophet, peace be upon him, defines faith as: "Something that is well established in people's minds and hearts, and to which credence is given by practice." So, faith cannot be treated as an academic theory or an abstract idea. Its practical effect has to be seen so that the claim of being a believer is seen to be true. Hence, Islam is embodied in statements and practices. The Prophet, peace be upon him, says: "Islam is built on five [pillars]: the declaration that there is no deity save God and Muhammad is His messenger, regular attendance to prayer, the payment of Zakah, the fasting in Ramadhan and pilgrimage to the Sacred House when a person is able to do so."
People who claim to be Muslims only because they have been born in Muslim families do not provide a practical proof of their claim. Yet, if they genuinely believe in the Oneness of God and the message of Muhammad, they are considered Muslims. If they do not go beyond that declaration, they are doing badly because of their negligence. They should be advised that their faith is not complete unless they attend to their Islamic duties.
On the other hand, we must not allow ourselves to assume the mantle of judges who pass judgment on people, claiming that certain people are true Muslims while others are not. If a person tells us that he is a Muslim, we take his statement at its face value. But if he does not confirm his statement by doing the duties God has imposed on Muslims, we advise him that he is exposing himself to the risk of God's punishment. Some of these people say that God is too merciful to punish them. They are not doing anything bad; they are simply not attending to their duties. This is a false argument.
A person who does not fulfill a duty God has imposed is certainly doing something bad. What is worse than the deliberate negligence of a duty God has imposed? Besides, a believer does not say that God will certainly forgive him. He certainly hopes for God's forgiveness, but he does not behave as though it is a certainty. He must always balance that hope with the fear that he might not be forgiven. That balance should provide a motivation for him to attend to his Islamic duties.