God chose Abram because he saw that Abram had faith and would follow Him faithfully.
God promised he would make him the father of many nations
Your reason of choosing something
the reason many ancient civilizations believed in gods was because they really didn't have much reason for many occurrences. If their was a hurricane or a volcanic eruption, it was because they thought the gods were mad at them. Having gods gave them a reason for things that at the time they couldn't explain.
Because gods ways are not our ways. he wanted to test Sarah faith.
According to Genesis 12:13, Abram feared that the king would kill him in order to have sex with his wife. Abram somehow knew that the king would not kill her brother for the same reason, so told the king that she was only his sister. For the same reason, he successfully deceived the king of Gerar by saying that his by now quite elderly wife really was his sister.
Check
your reason for choosing it
The same reason any civilization has had gods. To explain what was not known.
Abram Room's birth name is Room, Abram Matveyevich.
Abram Naroditsky's birth name is Abram Aronovich Naroditsky.
Abram Kozakov's birth name is Abram Naumovich Kozakov.
Abram Freydin's birth name is Frejdin, Abram Lvovich.