It is not necessarily the case that a person will lose all friends who are religious if they lose their faith. The outcome largely depends on the individuals involved, the nature of their relationships, and their willingness to accept and respect each other's beliefs or changes in beliefs.
Some people may find that their friends who are religious are understanding, empathetic, and open-minded enough to accept their friend's change in beliefs. In such cases, the friendship can continue to thrive even if there are differing perspectives on faith.
On the other hand, some friendships may be more tightly bound by shared religious beliefs, and a change in faith could create some tension or distance between the individuals. This is especially true if the friends are part of a tightly-knit religious community where conformity to specific beliefs is highly valued.
It is important to remember that friendships are built on a variety of factors, including shared interests, values, experiences, and emotional connection. While religious beliefs can be an important part of someone's identity, they are not the sole determinant of a meaningful friendship.
If a person is experiencing a shift in their beliefs, it might be beneficial to have open and honest conversations with their friends about the changes they are going through. By expressing their feelings and thoughts respectfully, they may discover that some friendships can adapt and grow despite differing beliefs, while others may naturally drift apart.
In any case, it's essential to surround oneself with people who respect and support each other's choices, even when they don't always see eye to eye on certain topics. True friends will embrace each other for who they are, regardless of their individual beliefs or faith.