The apostle John wrote this letter to believers. All instances of "you," "your," and "yours" include all believers and are plural. Here the words "we" and "us" refer to John and those who had been with Jesus. (See: [[rc://en/ta/man/translate/figs-you]] and [[rc://en/ta/man/translate/figs-exclusive]])
In verses 1-2 many pronouns like "that," "which," and "it" are used. They refer to "the Word of life" and "the eternal life." But, since these are names for Jesus, you can use pronouns that refer to a person like "who," "whom" or "he." (See: [[rc://en/ta/man/translate/figs-pronouns]])
The phrase "That which was from the beginning" refers to Jesus, who existed before everything was made. AT: "We are writing to you about the one who existed before the creation of all things"
The word "life" throughout this letter refers to more than physical life. It stands here for Jesus, the eternal life. (See: [[rc://en/ta/man/translate/figs-metonymy]])
This can be stated in active form. AT: "God made the eternal life known to us" or "God made us able to know him, who is eternal life" (See: [[rc://en/ta/man/translate/figs-activepassive]])
Here, "the eternal life" refers to the one who gives that life, Jesus. AT: "the one who enables us to live forever" (See: [[rc://en/ta/man/translate/figs-metonymy]])