How do we know that Jesus’ sacrifice was meant for specific people?

In his prophecy, Zechariah mentions that John would give knowledge of salvation by the remission of sins, emphasizing the specific nature of salvation as given to 'His people.' This implies that Christ's redemptive work was not simply a universal offer but aimed particularly at those whom the Father had chosen to save. The idea of particular redemption is reinforced in Reformed theology, showcasing how God's grace operates effectively to bring His elect to salvation, distinct from a general atonement that fails to achieve its purpose for all.