Low Sunday
Low Sunday is the first Sunday after Easter. It is called this because Easter is sometimes called High Sunday.
In early days of the Church, Easter was set as a day that people were baptized into the Church. They wore white garments for a whole week to show everyone what they had done and what they believe in.
The following Sunday they took off those garments and wore regular clothes. They were now members of the Church and subjected to her laws.
When we are baptized into the true faith we are also subjected to the Church and her laws. For belief in the Church you must believe all because if you do not believe then you are outside the Church.
To doubt and not believe are two different things. To doubt means you don’t understand and have questions. You accept the teachings of the Church but just can’t see how everything fits together so you ask and search. Nothing wrong with that.
To not believe means that you don’t believe that the Church is right in matters of faith. You can believe what ever you want and do what ever you want. Once you start on this road you are starting upon the path that will lead you outside the faith. This would be sad for not only the Church but for you as well.