ISB ~ 2 Timothy 1 v14

guard the truth:The gospel that Paul received from Jesus is a sacred deposit now entrusted to Timothy for safekeeping (1 Tim 6:20). His highest responsibility is to preserve it from corruption, to defend it from attack, and to pass it along complete and intact to his successors (2:2) (CCC 84, 256).

See introduction:Themes and Characteristics.