Abram (“father”) was the one who got the vision and because he believed enough to obey he became Abraham (“Father of nations”) and received the covenant by which we today come to Christ, but the knowledge of the One God stretches back through Noah to Adam. If you want to know who Adam is, read Genesis 5:2. No really, if you’re now thinking “Adam was the first man”, you should just take 5 seconds to read it.