Definition:
Common grace refers to the unmerited favor of God bestowed upon all of humanity, regardless of their spiritual state or relationship with Him. It is distinct from saving grace, which pertains to the redemption and eternal salvation of believers. Common grace encompasses the general blessings and goodness that God imparts to all people, sustaining creation and restraining evil.

Biblical Basis:
The concept of common grace is rooted in various passages throughout Scripture that highlight God's benevolence towards all of creation. In Matthew 5:45, Jesus teaches, "so that you may be sons of your Father in heaven. He causes His sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous." This verse illustrates God's impartial provision of natural blessings, such as sunlight and rain, to both the just and the unjust.

Psalm 145:9 further emphasizes God's universal kindness: "The LORD is good to all; His compassion rests on all He has made." This verse underscores the idea that God's goodness extends to all His creatures, reflecting His merciful nature.

Theological Implications:
Common grace serves several purposes within God's sovereign plan. Firstly, it acts as a means of preserving the world and maintaining order. By restraining the full extent of human sinfulness, common grace prevents society from descending into chaos and allows for the flourishing of human culture and civilization.

Secondly, common grace provides a context for the proclamation of the Gospel. By sustaining the world and granting humanity the ability to experience beauty, truth, and goodness, God creates opportunities for individuals to seek Him and respond to His saving grace.

Human Conscience and Moral Order:
Romans 2:14-15 speaks to the role of common grace in the human conscience: "Indeed, when Gentiles, who do not have the law, do by nature things required by the law, they are a law for themselves, even though they do not have the law. They show that the work of the law is written on their hearts, their consciences also bearing witness, and their thoughts sometimes accusing them and at other times even defending them." This passage suggests that common grace endows all people with an innate sense of morality, enabling them to discern right from wrong.

Restraint of Evil:
Common grace also functions as a restraining force against evil. In 2 Thessalonians 2:7, Paul writes, "For the mystery of lawlessness is already at work, but the one who now restrains it will continue until he is taken out of the way." While this verse primarily refers to the restraining work of the Holy Spirit, it also implies that God's grace limits the manifestation of evil in the world.

Cultural and Intellectual Achievements:
Common grace is evident in the cultural and intellectual achievements of humanity. The arts, sciences, and various fields of human endeavor reflect the creativity and wisdom that God imparts to all people. These achievements, while not salvific, demonstrate the image of God in humanity and contribute to the common good.

Conclusion:
Common grace is a testament to God's love and mercy towards all of creation. It highlights His desire for order, beauty, and goodness in the world, providing a foundation for human flourishing and the opportunity for individuals to encounter His saving grace.