The biblical definition of hope is "confident expectation." It is a firm assurance regarding things that are unclear and unknown.
Question: "What is the Christian's hope?"
Answer: Most people understand hope as wishful thinking, as in "I hope something will happen." This is not what the Bible means by hope. The biblical definition of hope is "confident expectation." Hope is a firm assurance regarding things that are unclear and unknown (Romans 8:24-25; Hebrews 11:1,7). Hope is a fundamental component of the life of the righteous (Proverbs 23:18). Without hope, life loses its meaning (Lamentations 3:18; Job 7:6) and in death there is no hope (Isaiah 38:18; Job 17:15). The righteous who trust or put their hope in God will be helped (Psalm 28:7), and they will not be confounded, put to shame, or disappointed (Isaiah 49:23). The righteous, who have this trustful hope in God, have a general confidence in God's protection and help (Jeremiah 29:11) and are free from fear and anxiety (Psalm 46:2-3).
The New Testament idea of hope is the recognition that in Christ is found the fulfillment of the Old Testament promises (Matthew 12:21,1 Peter 1:3). Christian hope is rooted in faith in the divine salvation in Christ (Galatians 5:5). Hope of Christians is brought into being through the presence of the promised Holy Spirit (Romans 8:24-25). It is the future hope of the resurrection of the dead (Acts 23:6), the promises given to Israel (Acts 26:6-7), the redemption of the body and of the whole creation (Romans 8:23-25), eternal glory (Colossians 1:27), eternal life and the inheritance of the saints (Titus 3:5-7), the return of Christ (Titus 2:11-14), transformation into the likeness of Christ (1 John 3:2-3), the salvation of God (1 Timothy 4:10) or simply Christ Himself (1 Timothy 1:1).
The certainty of this blessed future is guaranteed through the indwelling of the Spirit (Romans 8:23-25), Christ in us (Colossians 1:27), and the resurrection of Christ (Acts 2:26). Hope is produced by endurance through suffering (Romans 5:2-5) and is the inspiration behind endurance (1 Thessalonians 1:3; Hebrews 6:11). Those who hope in Christ will see Christ exalted in life and in death (Philippians 1:20). Trustworthy promises from God give us hope (Hebrews 6:18-19), and we may boast in this hope (Hebrews 3:6) and exhibit great boldness in our faith (2 Corinthians 3:12). By contrast, those who do not place their trust in God are said to be without hope (Ephesians 2:12, 1 Thessalonians 4:13).
Along with faith and love, hope is an enduring virtue of the Christian life (1 Corinthians 13:13), and love springs from hope (Colossians 1:4-5). Hope produces joy and peace in believers through the power of the Spirit (Romans 12:12;15:13). Paul attributes his apostolic calling to the hope of eternal glory (Titus 1:1-2). Hope in the return of Christ is the basis for believers to purify themselves in this life (Titus 2:11-14,1 John 3:3).