God called Abraham, why?You're still incorrect. You're the one who calls His plan random. He doesn't call it that. You do.
Also, there is not a thing about the ambigous relationship of God and Enoch that suggests it was random. That's just a false non-theological unscriptural term you've used to label it with in reference to the world of God in election. Obviously it was God who has Himself chosen all of His people. This is dogma, and applies here as well. It also dismantles your proof-text and feeble theology.
That you don't like it doesn't do a thing to this truth of Scripture.
Because Abraham believed God and it was imputed unto him for righteousness sake.
God called Enoch. Why? Because Enoch walked with God.
God called Noah. Why? Because he was a Godly man who was righteous in the sight of God and had found grace in his sight.
This is what the Scripture teaches. If you deny these very basic truths in the light of your own preconceived ideas, then you have allowed yourself to be brainwashed by some other man's system of theology instead of plain biblical teaching.