Do you believe?

To not yet believe in the resurrection means you are not yet a believer.

1 Corinthians 15:12–15 ESV

Now if Christ is proclaimed as raised from the dead, how can some of you say that there is no resurrection of the dead? But if there is no resurrection of the dead, then not even Christ has been raised. And if Christ has not been raised, then our preaching is in vain and your faith is in vain. We are even found to be misrepresenting God, because we testified about God that he raised Christ, whom he did not raise if it is true that the dead are not raised.

Baker Encyclopedia of Christian Apologetics Greek versus Christian Concept of Immortality

Greek versus Christian Concept of Immortality. Greek and Christian concepts of immortality differ (see Ladd). According to an ancient Greek concept of immortality (e.g., Plato), human beings are a soul and only have a body. The soul is to the body what a rider is to a horse. Salvation is in part deliverance from the body, which is the prison of the soul. There is a basic duality of soul and soma (body).

Baker Encyclopedia of Christian Apologetics Greek versus Christian Concept of Immortality

The Hebrew-Christian tradition, on the other hand, while acknowledging that the soul and body separate at death, holds to a unity of the spiritual and physical dimensions of human nature. The human being is a souled body. The soul is to the body what form is to matter, or shape is to a vase. Hence, salvation is not salvation from the body but salvation in the body (see RESURRECTION, PHYSICAL NATURE OF). Indeed, the word immortality is used of human beings in the New Testament exclusively in the context of the resurrection body (1 Cor. 15:53; 2 Tim. 1:10).

1 Corinthians 15:53 ESV

For this perishable body must put on the imperishable, and this mortal body must put on immortality.

Resurrection has always been believed, Old Testament and New Testament.

Job 19:25–27 ESV

For I know that my Redeemer lives, and at the last he will stand upon the earth. And after my skin has been thus destroyed, yet in my flesh I shall see God, whom I shall see for myself, and my eyes shall behold, and not another. My heart faints within me!

John 20:24–25 ESV

Now Thomas, one of the twelve, called the Twin, was not with them when Jesus came. So the other disciples told him, “We have seen the Lord.” But he said to them, “Unless I see in his hands the mark of the nails, and place my finger into the mark of the nails, and place my hand into his side, I will never believe.”

John 20:26–28 ESV

Eight days later, his disciples were inside again, and Thomas was with them. Although the doors were locked, Jesus came and stood among them and said, “Peace be with you.” Then he said to Thomas, “Put your finger here, and see my hands; and put out your hand, and place it in my side. Do not disbelieve, but believe.” Thomas answered him, “My Lord and my God!”

John 20:29 ESV

Jesus said to him, “Have you believed because you have seen me? Blessed are those who have not seen and yet have believed.”

Romans 10:8–10 ESV

But what does it say? “The word is near you, in your mouth and in your heart” (that is, the word of faith that we proclaim); because, if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. For with the heart one believes and is justified, and with the mouth one confesses and is saved.

Sometimes we the messengers, make faith to complicated, to difficult to believe. We expect peoples theology to be perfect before they come.

To expect an unbeliever to have perfect theology before they come, is like expecting a dead man to swim.

What then must I believe to be saved?

You must believe Jesus is the Son of God, that He died for your sins, and that He rose again.

Greek-English Lexicon of the New Testament based on Semantic Domains 31.85 πιστεύω; πίστις, εως

to believe to the extent of complete trust and reliance—‘to believe in, to have confidence in, to have faith in, to trust, faith, trust.

The believer will say, “you ask me why I know he lives, He lives within my heart!

Romans 8:11 ESV

If the Spirit of him who raised Jesus from the dead dwells in you, he who raised Christ Jesus from the dead will also give life to your mortal bodies through his Spirit who dwells in you.