"Let us labour therefore to enter into that rest, lest any man fall after the same example of unbelief." (Hebrews 4:11 KJV)
"You can enter God's Kingdom only through the narrow gate. The highway to hell is broad, and its gate is wide for the many who choose that way. But the gateway to life is very narrow and the road is difficult, and only a few ever find it." (Matthew 7:13-14 NLT)
Here is what I feel is a challenging example of where some people might get off the path, having felt as though they were safe and secure. We sometimes feel as though we have everything under control, as if we have reached a certain point of maturity, and we don't need to worry about falling into sin, as if that old nature is gone and there is no need to struggle or watch our steps. How I wish that those days never had happened, because they are brutal and cause serious damage!
That said, the Lord is faithful and always willing to forgive our stupidity and unfaithfulness; whatever the reason, it is always because we have let ourselves step outside of His protection and security! Plain and simple; thinking we have achieved or can handle things on our own, we make ourselves vulnerable to the enemy's attack. Not that he doesn't attack us when we are walking closely, because he is always looking for a way to trip us up or cause us to stumble.
I find that the harder I try to serve the Lord, the more attacks I get from the enemy. If we are not doing much to serve the Lord, then the enemy pretty much leaves us alone; but as soon as we start doing what God tells us to do, we find that things are difficult and out of control.
The good news about all of that, being difficult and out of control, is that none of that craziness really matters! I mean, sure, we might feel as though we need to worry and make ourselves feel vulnerable to the enemy's attack; but when we give everything over to God, making ourselves humble, He will always make a way for everything to work for the good, in one way or another...
""Anyone who listens to my teaching and follows it is wise, like a person who builds a house on solid rock. Though the rain comes in torrents and the floodwaters rise and the winds beat against that house, it won't collapse because it is built on bedrock. But anyone who hears my teaching and doesn't obey it is foolish, like a person who builds a house on sand. When the rains and floods come and the winds beat against that house, it will collapse with a mighty crash."" (Matthew 7:24-27 NLT)