The abstract noun "commandment" can be stated as "command." AT: "This is what God commands us to do: Believe ... just as he commanded us to do" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
The close union of believers is expressed by the terms "remains in him." See how "remains in God" was translated in [1 John 2:5-6](../02/04.md). (See: [[rc://en/ta/man/translate/figs-metaphor]])