How do we know that Christ's sacrifice allows for our adoption?

Christ's role as the adoptive parent is pivotal for our salvation and adoption. He was not only willing but was also fit to make the payment required for our sins, as stated in 2 Corinthians 5:21, where He was made sin for us even though He knew no sin. His sacrifice on Calvary fulfilled the law's demands, allowing God the Father to adopt sinners legally. Consequently, justice was satisfied, which allows all who are called into His family to be viewed as His children, cleansed and justified by His blood. This guarantees not just legal standing with God but eternal fellowship, hence proving the veracity of our adoption in Christ.