As we are under the covenant of grace, we are secured against departing from the living God by the sure declaration of the covenant. ---- Charles Spurgeon
And I will establish my covenant between me and you and your offspring after you throughout their generations for an everlasting covenant, to be God to you and to your offspring after you. I will be their God (Genesis 17:7-8).
For this is the covenant that I will make with the house of Israel after those days, declares the Lord: I will put my laws into their minds, and write them on their hearts, and I will be their God, and they shall be my people (Hebrews 8:10).
My sheep hear my voice, and I know them, and they follow me. I give them eternal life, and they will never perish, and no one will snatch them out of my hand. My Father, who has given them to me, is greater that all, and no one is able to snatch them out of the Father's hand. I and the Father are one (John 10:27-30).
Now may the God of peace who brought again from the dead our Lord Jesus, the great shepherd of the sheep, by the blood of the eternal covenant, equip you with everything good that you may do His will, working in us that which is pleasing in His sight, through Jesus Christ, to whom be glory forever and ever. Amen (Hebrews 13:20-21).