If you start on the path of following Jesus, how do you know you will stay on the path? How do you know you will not drift away?
Over the course of my life I have known many who have been faithful through the years. I have also known many who started to drift and then had their lives crumble. How can we be assured that we will be on the right side of the divide?
I have two comments for you. The first is right answer, given by directly from the mouth of Jesus. The other is my observation.
First the right answer. As recorded in Matthew 7:24-27:
Therefore everyone who hears these words of Mine, and acts upon them, may be compared to a wise man, who built his house upon the rock. And the rain descended, and the floods came, and the winds blew, and burst against that house; and yet it did not fall, for it had been founded upon the rock.
And everyone who hears these words of Mine, and does not act upon them, will be like a foolish man, who built his house upon the sand. And the rain descended, and the floods came, and the winds blew, and burst against that house; and it fell, and great was its fall.
Jesus indicates that it is not enough to merely hear His words. We need to act upon them. If we do so, when the troubles of life come and our faith is tried, our house will stand. But if we hear but don’t act, then when the trouble comes, our house will collapse.
Now here is my observation. I do not remember anyone that met daily with God in heart-to-heart fellowship that lost their faith. There may be some out there, but I cannot list any.
Another way of saying this is that of all the people I know that their faith crashed and burned, an early warning that their faith was loosing altitude and their life was headed for a crash is that they were not meeting daily with the Lord. Some were keeping up appearances, but then their lives crashed.
Have a heart-to-heart with God daily. Be a doer and not merely a hearer. You will enjoy a long lasting relationship with God that will last through the difficult times.