Read Romans 2.
The opening chapters of Romans presents God's condemnation of sin. His eternal wrath is being "stored up" for that day when the unrepentant will experience His judgment. The severity of the penalty will be "to each one according to his works" (v.6). Revelation 20:11-15 describes the scene that will take place. The lake of fire is called the second death. Jesus said in Mark 9:44-49 that the torment will be "unquenched."
How could a loving God do such a thing?
The answer is that those who will endure such punishment brought this upon themselves. It is not God's fault at all. They sinned against God and refused to believe there would be consequences for their actions. Further, they willfully rejected the only way of escape that He provided for them. No one will be blaming God on that day. Each person will acknowledge their guilt. They knew. So, they are without excuse (v.1)
How does God reveal His standards of what is right and moral?
In chapter one, God naturally reveals His "eternal power and divine nature" through creation. With appreciation to John A. Witmer in the Bible Knowledge Commentary on Romans, there three ways God reveals His expectations of right and wrong in this chapter.
1. Truth (vv. 2-4)
He is the God of truth (Isaiah 65:16). Jesus said, "...true worshipers will worship the Father is spirit and in truth" (John 4:23). "...your word is truth" (John 17:17). "All Scripture is breathed out by God..." (2 Timothy 3:16). This is the basis of God judgments and expectations of each person. Once an individual rejects the Scriptures as totally true and accurate then they are subject to the consequences.
2. Impartiality (vv.5-11)
In that day, it will not matter of one's race, color of skin, parentage, upbringing, religious affiliation, financial condition, philanthropy, skills, or achievements. There will be no bragging or excuses. "By nature" (v.14), "on their hearts while their conscience also bears witness" (v.15), the Holy Spirit drew them toward the truth. But they deliberately chose to go their own way. "Self-seeking" (v.8), or contentious against God, even provoking Him, they hardened their own hearts and became impenitent (v.5).
3. Jesus Christ (vv.12-16)
The Apostle Paul wrote, "...on that day when, according to my gospel, God judges the secrets of men by Christ Jesus." (v.16) To the Philippians he wrote, "...so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of the Father." (Philippians 2:10-11)
Why does God wait to execute His eternal judgment?
Many people feel that since they have not suffered consequences already for their sin, that God will not punish them in the future, or there is no such punishment. Others have suffered greatly due to their personal sin and yet rejected God's attempt to draw them to Jesus. "Or do you presume on the riches of his kindness and forbearance and patience, not knowing that God's kindness is meant to lead you to repentance?" (v.4) "The Lord is not slow to fulfill his promise as some count slowness, but is patient toward you, not wishing that any should perish, but that all should reach repentance." (2 Peter 3:9)