Do we have to believe in a literal creation to be saved?

TL;DR:

Belief in a literal six-day creation is not required for salvation, but core doctrines about God, sin, and Jesus are. While views on creation may differ among true Christians, any creation view that denies foundational truths about Adam, sin, and Christ’s saving work can undermine the gospel.

what does the bible say?

A true Christian believes in key core doctrines, such as belief in God as defined in Scripture, in Jesus as fully God and fully human, and in His virgin birth. These are called “core” doctrines because denying them undermines Jesus’ work as the sinless God-man who lived perfectly and died in the place of sinners. In short, salvation is based on acknowledging God as holy (Isaiah 6:3; Habakkuk 1:13; Psalm 5:4–5; 1 Peter 1:16), our sinfulness (Genesis 6:5; 9:21; Psalm 14:1-4, 51:5; Romans 3:23), and Jesus as the only way to escape God’s wrath against sinners (John 14:6; 1 Thessalonians 1:10).

The age of the Earth isn't among these core doctrines because it does not directly undermine them. That said, not believing in a literal creation can be problematic indirectly if it leads to denying a historical Adam (contra Genesis 2; Matthew 19:4–5) or the entrance of death through sin (contra Genesis 2:17; 3:17–19; Romans 5:12). Taking that stance may reveal a tendency to elevate modern science over Scripture’s authority.

from the old testament

Salvation requires a correct understanding of who God is and who we, as sinners, are. Scripture teaches that God is holy (e.g., Isaiah 6:3). Being holy means that not only does God not sin, but He also hates sin in others (Habakkuk 1:13; Psalm 5:4–5) and must punish it to maintain His holiness.
While God created us to be holy like Him, we rebelled against Him (Genesis 3:6). The result of that was the entry of sin and death into the world (Genesis 2:17; 3:17–19). The result is that we are all born sinful (Psalm 51:5), with God considering us all evil (i.e., Genesis 6:5; 9:21; Psalm 14:1–4).
The Old Testament presents Adam and Eve as historical figures, created on the sixth day (Genesis 1:26–31), with all of creation completed in six days (Genesis 2:1–3). That's a straightforward, literal reading of the account, but some true Christians have argued for various evolutionary-based readings. Such ideas do not directly undermine the gospel but could lead to confusion over what in Scripture is literal and what is figurative. Unabated, such challenges can chip away at a core theological foundation of Scripture: that sin, death, and judgment entered the world through Adam and Eve. When that happens, there is a risk of undermining the reason humanity needs to be reconciled to God and of becoming a challenge to the gospel.

from the new testament

The New Testament teaches certain key, core doctrines about sin and Jesus that must not be denied. Namely, through Adam sin and death entered humanity: “just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned” (Romans 5:12). Also, sin is rebellion against God (1 John 3:4), and salvation is about being saved from His coming wrath against sin (Romans 5:9).
We are unable to save ourselves, and salvation only comes through Jesus (John 14:6). Though He was always fully God (John 1:1), Jesus also took on real, full humanity to be like us (Philippians 2:6–7). Jesus was born into humanity sinless and uncorrupted through His virgin birth (Matthew 1:18–23). Thus, He did not have the internal corruption that came through Adam. Also, unlike Adam, He did not succumb to external temptations to sin. This perfection enabled Him to die in the place of sinners.
While explaining marriage, Jesus said, “Have you not read that he who created them from the beginning made them male and female” (Matthew 19:4). This indicates that Jesus treated Genesis 2 as literal history. That’s a serious challenge for those who interpret it figuratively, and regardless of one’s view of creation, believers can't deny what Jesus affirmed.
Paul wrote, “I delivered to you as of first importance what I also received: that Christ died for our sins in accordance with the Scriptures, that he was buried, that he was raised on the third day in accordance with the Scriptures” (1 Corinthians 15:3–4). Notice that “how creation happened” is not listed as “first importance” because it’s the gospel, not one’s view of creation, that saves.

implications for today

Doubt can poison our receptiveness to truth. Holding a figurative view of the creation account risks cultivating doubt about other "problematic" parts of Scripture, the parts that are foolishness to the world: Jesus’ death and resurrection (1 Corinthians 1:18). Those truths are the core of the Christian faith (1 Corinthians 15:19).

Other risks are being unloving toward our Christian brothers and sisters and being prideful about our position. We must treat other believers with love on this issue. Jesus taught us that the world knows we are His by our love for one another (John 13:35). We should never compromise the gospel, but we also shouldn't besmirch it by disparaging one another. Pride is another pitfall—either the pride of knowing scientific evidence better or the pride of not being swayed by worldly thinking.

Ultimately, we must never add requirements to salvation that go beyond what Scripture. If we do, we start teaching another gospel that really isn’t a gospel at all (Galatians 1:6–9).

understand

Salvation depends on affirming core doctrines about God’s holiness, human sin, and Jesus Christ’s person and work.
A specific view of creation is not itself a gospel essential.
Denying a historical Adam or the entrance of death through sin can undermine the theological foundation of the gospel.

reflect

How do you understand which doctrines are truly essential to salvation and which are important but secondary?
How does your view of creation strengthen or weaken your confidence in the authority of God's Word?
How can you hold firm convictions about Genesis while maintaining humility and unity with other believers who have different understandings or leanings?

engage

How does Romans 5:12–19 connect the historical Adam to the saving work of Christ, and why is this important for our faith?
How does Jesus' use of Genesis in Matthew 19 inform the way Christians interpret the creation account?
What criteria should be used to distinguish core doctrines from secondary ones, and how can we uphold our convictions in a winsome and godly way?