What guarantees the preservation of true believers until the end?

According to Scripture, the preservation of true believers is secured by God's omnipotent power. In Ephesians 1:13-14, the Holy Spirit is described as a seal and an earnest of our inheritance, assuring us of our eternal security. Additionally, Jude 24–25 promises that God is able to keep believers from falling and presents them faultless before His glory. This divine preservation illustrates that salvation does not rest on human effort but on God's faithful commitment to His people, emphasizing the believer's secure and sustained relationship with Him.