God is a faithful God. He stands by His promises; over 1,000 generations (so, forever; Deuteronomy 7: 9).
And He will not start with you to not keep His promises.
If devils and demons want to put doubts in your mind and in your heart, then counter with the promise of Jesus:
“My sheep listen to my voice; I know them, and they follow me. I give them eternal life, and they shall never perish; no one will snatch them out of my hand. My Father, who has given them to me, is greater than all; no one can snatch them out of my Father’s hand.” (Jesus in John 10:27-29; NIV)
Believe God (your friend); Do not believe the devil (your enemy).
Say this out loud: Help me, Jesus, that I am more and more aware that I am saved forever and reconciled to God (or, of course ,in your words).