Please find below the conjugation of ser and estar once again for repetition:

Both ser and estar are translated into English as to be. In Spanish, there is a difference in the meaning of ser and estar. A first rule for using of estar was already given, which says that estar is more related to a location or a temporary condition. In the same way, we can assume a general rule for ser, which says that characteristics that are inherent to a subject are described with the verb ser. Furthermore it's quite a nice rule of thumb to say that after estar it's rather unusual to put a noun. Some few exceptions might be possible like:

Es medico, pero ahora está de camarero = He is a doctor but at the moment he is a waiter.

However, for other characteristics and features of subjects ser is used:

incorrect: Maria está estudiante
correct: Maria es estudiante = Maria is a student

Always when asking and giving the time the verb to be used is ser.

There are more than one possibility in Spanish to form a passive voice. One of them is the one with ser that we'll have a look at now. In Intermediate Lesson 1.6 you'll see details on passive voice with the reflexive verb.

This passive voice is formed with the verb ser and the perfect participle (yes, the one we already had with the compound tenses). Here there is a little extra because the perfect participle is in gender and number identical with the subject. That means that depending on the subjects gender the participle gets the same ending. Is the subject a feminine noun in singular the participle gets an a; is the subject a masculine noun in plural the participle gets the ending os. An overview is given in the table:

The passive voice can have all the tenses that we have already seen. The verb ser is conjugated in the tense accordingly and the perfect participle is added (always in accordance with gender and number!!). Here you have an overview over the possibilities with the tenses that we have seen with the sentence You are baptised.

The table shows the theoretical possibilities but as always, some of the forms are used rather seldom. For instance:

instead of
Vosotros habéis sido bautizados (You had been baptised.)
a Spaniard would say:
Os han bautizado (They have baptised you.) or Se os bautizó (You were baptised)

The difference of ser and estar lays in the duration of the state that is talked about.

Las fresas son rojas. = Strawberries are red. They are usually and always red. However, if the state is only temporary and it is to be expected that it changes eventually then estar is to be used:

Las fresas están verdes todavía! = The strawberries are still green! But it is to be expected that they will turn red eventually and then they are perfect strawberries that are red as they are supposed to be.

If the verb to be is used in the meaning of a location the right translation is estar. Even if it doesn't sound too good but still - if you can substitute the verb to be with to be located then it is definitely estar!