Jeremiah 32:40 “I will make with them an everlasting covenant, that I will not turn away from doing good to them. And I will put the fear of me in their hearts, that they may not turn from me. 41 I will rejoice in doing them good, and I will plant them in this land in faithfulness, with all my heart and all my soul.”
The ground of our assurance of final perseverance and salvation is a covenant keeping God. Dr. John Piper explains in this 3 minute video excerpt:
We Should Learn This Verse from Desiring God on Vimeo.
(1) The paperback version of “Twelve What Abouts – Answering Common Objections Concerning God’s Sovereignty in Election” is currently available at a 50% discount direct from the publisher, Solid Ground Christian Books. For those who wish to order 10 or more copies there is a 54% discount. Both deals can be found at 
Michael P. Jensen’s book “How to Write a Theology Essay” could prove to be a valuable resource for anyone wishing to help people grasp true things about God. Each of the twenty chapters ends with a bullet-point summary (though there is more to the book than the summaries):