We describe both of these passages below, with rebuttals.

Romans 1: Argument from design:

Romans 1:18 to 20 states:

"For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness; Because that which may be known of God is manifest in them; for God hath shewed it unto them. For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse." ₁

That is, when a person looks around at the design of the stars; sun; moon; planets; the world and its oceans, mountains, valleys canyons, plants, and animals; and the rest of the universe, they see multiple proofs for the existence of God. There is no excuse for anyone to deny God's existence or creative power.

This is basically Paul's version of the argument for the proof of God's existence from design. Atheists are without excuse, since they only need to look at creation and be forced to conclude that the universe must have had a creator with superhuman/supernatural powers. That is one definition of a God.

A rebuttal:

Whenever a statement is encountered in the Bible, it is important to determine whether:

It can be argued that Paul's statement was applicable in the first century CE when he wrote it, but is not necessarily meaningful today.

In the middle of the first century CE, when people believed in a three tier universe composed of a flat earth, a metallic dome above that supported Heaven, and the space between the dome and earth. Living in a pre-scientific culture, they had no concept of the Big Bang about 14 billion years ago, the development of the universe, the origin of the solar system, that the earth rotates around the sun, the coalescence of the Earth about 4.5 billion years ago, the emergence of single-celled life, and evolution of the species of animals, etc. With the rise of of modern cosmology, geology, evolution, as well as studies of the origins of religion, higher criticism of the Bible, and the quest for the historical Jesus, people in the 21st century have the necessary framework to begin to understanding how the universe developed without a creator, and how the Bible writers formed their beliefs.

People in the first century CE may have had no excuse for having no belief in God. However, many people in the twenty-first century are able to defend their lack of belief in God from the observations and conclusions of science.

Romans 2: Beliefs written by God onto their conscience:

Romans 2:15 states:

"Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another." (KJV) ₁

That is, even people who have not been exposed to the Bible have God's standards "written in their hearts" as part of their development as human beings. In Biblical times, the heart and kidneys were believed to the organs where human thoughts arose and were stored. In modern times, his is often expressed as God inserting an awareness of his law into everyone's conscience.

These two passages from Romans might have inspired the following attacks on Atheists, Agnostics and non-Christians:

"... the most depraved men cannot wholly escape the voice of God. ... [Efforts] to destroy or bury the voice of God that comes to him through nature, which includes his own consciousness" can never succeed." ₂

"God has ensured that those who question his existence, along with those who reject him out of hand, have not a shred of moral integrity in doing so...The Bible makes it clear that those who reject God outright, and those who claim to be sitting on the fence, are refusing to acknowledge what they know to be true." ₃