What does the Bible say about encouraging words for believers?

In Zechariah 3, God reassures His people through the vision of Joshua the high priest, who stands before the Lord despite his filthy garments representing sin. The Lord rebukes Satan, reminding us that it is not our own works or decisions that maintain our relationship with God, but His sovereign choice and grace. This vision serves as a reminder that God's encouragement is rooted in His power and promises to cleanse and redeem His people, assuring them of their identity and place in His plan of salvation.