"The Lord directs the steps of the Godly. He delights in every detail of their lives. Though they stumble, they will never fall, for the Lord holds them by the hand." Psalm 37:23-24
The promise to never fail is conditional. You have to put your faith into God. You have to trust the relationship. You have to believer that God is there protecting you. It will give you the confidence to walk with Jesus boldly. The more you mold your life to be like Jesus the more you see how much God is protecting you. He is holding your hand as you walk in step, so that if you start to fall he can keep you from going head first into trouble. You may lose your step for a minute, but you do not fall. He will not allow His enemies to destroy you.
This promise is all about God's grace. He knows you are not perfect, but He also knows your heart. If you love Him and try to put that relationship first, then you will find mercy. Where some people may self-destruct, God will help you get through. He is there supporting you. He will sustain you when you have nothing left to give. He takes pleasure providing for you. It pleases Him to see your gratitude and good attitude that comes from what He provided for you.
It is like when you go hiking. It has hard parts where you think you can't go another step. God will keep you from falling. He will wait on you when you go slow. He will keep you from going over the edge when you are tired and not paying as close attention. You may trip occasionally, get muddy, get sweaty, scrap your hand or knee, but you will not break bones, walk into peril, or die. He keeps you from injuring yourself where you can't go further in your journey. He is everything you need on that hike. He provides what you do not have. You will not make it on your own. You need Him to keep your steps secure. Same goes for exploring caves. He is the light that shows you where to go in the darkness.
1 Samuel 2:9, Psalm 34:19-20, 37:23-24, 40:2, 91:12, Proverbs 24:16, Micah 7:8, & 2 Corinthians 4:9