How do we know that the elect are the true children of Abraham?

Scripture reveals that the true children of Abraham are those who believe in Christ, as seen in Galatians 3:29, which states that if you belong to Christ, then you are Abraham's seed and heirs according to the promise. This reflects God's sovereign grace, wherein His elect, called by His name, represent the spiritual heirs in accordance with His covenant. Romans 9:8 confirms that it is the children of the promise who are counted as Abraham's descendants. This illustrates that God's election transcends cultural and ethnic identity, establishing faith as the basis for being considered His children.