"Jesus has become a surety of a better covenant" (Hebrews 7:22). A surety is a guarantee. In Bible days, the word surety was used to describe someone who guaranteed another person's debt would be paid. All of us have a sin debt to God. The good news is Jesus paid it all. Jesus Christ is your surety.
We all have a sin debt to God. We have broken God's law. Our conscience testifies as much. The good news is Jesus paid it all. Look to the cross of Jesus, where He died in our place. Our sin debt to God's justice was paid, not in part but the whole. Believers are free from a debt that we could never repay. 
Be saved and sure based on the promises of God. In the new covenant, God makes four promises to every believer, guaranteed through Jesus Christ (Jeremiah 31:31-34; Hebrews 8:7-13). These promises are: (1) God will put His laws in your mind; (2) God will be your God and we are His people; (3) We will all know the Lord; (4) God will forgive your sins and remember them no more.
Be saved and sure based on the promises of God. In the new covenant, God makes four promises to every believer, guaranteed through Jesus Christ (Jeremiah 31:31-34; Hebrews 8:7-13). These promises are: (1) God will put His laws in your mind; (2) God will be your God and we are His people; (3) We will all know the Lord; (4) God will forgive your sins and remember them no more.
Be saved and sure believing the gospel. Christ died for your sins. He is risen from the dead for your justification. You are a child of God by faith in the Lord Jesus (Galatians 3:26). Jesus intercedes for believers, that the Father will "keep them from the evil one" (John 17:15). This is the present day ministry of Jesus, as your High Priest (Hebrews 7:20-25). Jesus shall return to glorify all who believe in Him (1 John 3:2). Be saved and sure by faith alone in the Lord Jesus Christ.