My little children, I am writing these things to you so that you will not sin. But if anyone does sin, we have an advocate before the Father—Jesus Christ, the Righteous One. He Himself is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world. — 1 John 2:1,2
Here's the promise that anchors every anxious heart: Jesus gives His sheep eternal life, and they shall never perish. No one can snatch them out of His hand — and they're also in the Father's hand. That's a double grip, and neither hand will let go. Your security doesn't rest on how well you're walking today; it rests on the finished work of the Good Shepherd who laid down His life for the sheep. If you're in His hand, you're safe.