Why is Abraham father of Christians?

Abraham is considered the father of Christians because he is a foundational figure in the Judeo-Christian tradition, recognized for his faith and covenant with God. In Christianity, he is viewed as a model of faith and righteousness, and his belief in God's promises is seen as a precursor to the faith that Christians are called to embody. Additionally, the New Testament often references Abraham to illustrate themes of faith and justification, establishing a spiritual lineage that connects Christians to the patriarch.