en_tn/act/01/01.md

The former book I wrote

The former book is the Gospel of Luke.

O Theophilus

Luke wrote this book to a man named Theophilus. The word “O” is used because Luke was addressing him. Some translations follow their own culture's way of addressing a letter and write "Dear Theophilus" at the beginning of the sentence. Theophilus means "friend of God." (See: rc://en/ta/man/translate/translate-names)

until the day that he was received up

This refers to Jesus' ascension into heaven.

command through the Holy Spirit

The Holy Spirit led Jesus to instruct his apostles on certain things.

after his suffering

This refers to Jesus' suffering and death on the cross.

appearing to many others

Jesus appeared to many of his disciples beyond the original 12 apostles.