The world points beyond itself
The Bible opens with God as the maker of the universe, not as one more thing inside it (Genesis 1:1). David looked at the sky and saw it as a continuing sign of God's glory. Paul made a similar argument to the Christians in Rome, saying that creation reveals God's eternal power and divine nature (Psalm 19:1; Romans 1:20).
That doesn't settle every question about science, suffering, or how the universe works. Christians have wrestled seriously with those questions. Still, Scripture invites us to see the beauty, order, and existence of the world as clues that reality may have a Creator, rather than being only a purposeless accident.
The heavens declare the glory of God; and the firmament sheweth his handywork.
Jesus is central to the Christian answer
For Christians, the strongest answer is not simply an argument from nature. It is Jesus. John's Gospel identifies Jesus as the eternal Word who was with God and was God, then says that this Word entered human life in flesh and blood (John 1:1; John 1:14). The Christian claim is that God has not remained hidden or distant.
Jesus' death and resurrection stand at the heart of this claim. Paul reminded the divided church in Corinth that Jesus died for sins, was buried, rose again, and appeared to Peter and the Twelve (1 Corinthians 15:3-5). You may not be ready to accept that testimony straight away. But it gives you something concrete to investigate: the person, teaching, death, and reported resurrection of Jesus.
And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.
Questions do not shut God out
Doubt can feel lonely, especially if other people sound certain. Yet one of Jesus' own disciples, Thomas, struggled to believe the reports that Jesus had risen. When Jesus met him, he addressed Thomas's real need and called him towards faith (John 20:27). Thomas then recognised Jesus as his Lord and God (John 20:28).
Honest doubt is different from refusing to consider any answer. You don't need to manufacture certainty before you begin. Read one of the Gospels, perhaps John, slowly. Notice what Jesus does with people who are afraid, wounded, confused, or sceptical. Then ask what best explains him.
Then saith he to Thomas, Reach hither thy finger, and behold my hands; and reach hither thy hand, and thrust it into my side: and be not faithless, but believing.
Take the next honest step
Biblical faith is not pretending that unseen things are unreal. It is a settled trust in God that reaches beyond what we can currently prove or control (Hebrews 11:1). The same chapter says that God responds to those who diligently seek him (Hebrews 11:6). Seeking can include thinking carefully, asking hard questions, praying, and speaking with mature Christians you trust.
God's invitation is personal. Through Jeremiah, God told his people that wholehearted seeking would lead them to find him (Jeremiah 29:13). If you aren't sure how to pray, start simply: God, if you are real, help me know the truth. Then stay open, keep asking, and give Jesus a fair hearing.