This is not correct. No person has seen God the father except his son, except Jesus did say that if you had seen him you had seen the father. The meaning of this section of Romans is that they have seen God spiritually, yet they have chosen to worship other things instead: idols, sexual extremism, envy, etc.
"They are filled with every kind of unrighteousness, wickedness, covetousness, malice. They are rife with envy, murder, strife, deceit, hostility. They are gossips, slanderers, haters of God, insolent, arrogant, boastful, contrivers of all sorts of evil, disobedient to parents, senseless, covenant-breakers, heartless, ruthless."
Science, reason, nature, Allah, etc. are not mentioned. What is keeping people from God is their attitudes and evil actions that they do by choice.