Why do Christians believe God will come again?

Hebrews 10 and Revelation 22 explicitly state the promise of Christ's return, reinforcing the Christian hope in His second coming. This belief is rooted in the trustworthiness of God's Word and His covenant promises. The certainty of His return serves as a motivation for believers to live in holiness and anticipation, knowing that Christ will fulfill His promise to return and establish His eternal Kingdom. Thus, this expectation also compels believers towards purity and readiness as they await His coming.