For most Israelites of the Old Testament, the historical event that formed the basis of their faith was the Exodus. The preamble of the
Ten Commandments, read with the Decalogue, was read at least annually, and reminded the Israelites of the reality of God through His
historical work (Ex 20:2).
God is real, because He freed the nation of Israel from slavery in Egypt.
God is real, because He is faithful to His promises. The Exodus was a partial fulfillment of the Abrahamic Covenant
(Gen 15:13-14; Ex 2:24).
Faith has a basis in historical fact with a view towards the future as God fulfills His covenants.
Abraham (Gen 15:6) is noted as a great example of faith in the New Testament
(Rom 4:3; Gal 3:6;
Abraham leaves his home, from Haran to Egypt, on God's verbal promise of the future
Despite the age of him and his spouse, Abraham believes in God's promise of an heir
Abraham had no historical basis that God was real!