You need not be baptized to add a Christian Name or given name or first name to your original name. The use of the term “Christian Name” can sometimes cause confusion to individuals.
For example, if I wish to add “John” to my existing name of Ong Tan Kong, you need not be baptized or be a Christian or Catholic to add “John” to your name. A more apt term to use is “First Name” instead of “Christian Name”.
However, we understand that ICA may allow you to add your Christian Name as appearing in your Baptism Certificate without the need of a Deed Poll.