This "looking back" is not merely reflecting to evaluate the progress made since one decided to leave the world. Instead, it is like Lot's wife, who looked back with a degree of longing to return to what she had left. Her life was literally on the line, and rather than being fully engaged in surviving, she placed a higher priority on life's lesser matters than on the greater one of preserving her life through God's gift of protection.
She looked back, revealing her heart still to be in Sodom, a type of the world. Her action indicates regret for having left. Success in God's way requires following an awesome vision of future glory with devoted conviction. Abraham is a primary example: He looked for a city built by God, apparently leaving his homeland without ever looking back (Hebrews 11:8-10, 13-16).
Once we commit to Christianity, God's calling becomes our vocation, which requires our concentrated attention going forward. A vocation is a person's regular occupation. What happens when a Christian looks back with a measure of longing is similar to someone talking on a cell phone while driving his car. He frequently drifts all over the road, swerving this way and that because, at best, his attention is split between conflicting priorities. He is setting himself up for trouble, and all too frequently, an accident occurs. A Christian cannot make a beeline for the Kingdom with his attention diverted elsewhere. We are not to be anything but altogether followers of the Son of God. The stakes are that high, for the fulfillment of His promise is so great.
Dramatic, sudden death, as happened to Lot's wife, will not likely happen to us if we gaze yearningly behind us. For this reason, a person who has begun to fall away will most likely take the second step backwards with hardly a pause. Hebrews 10:39 says, "But we are not of those who draw back to perdition, but of those who believe to the saving of the soul." Almost invariably, longing for the old life is followed by gradually and increasingly believing that God's requirements are too exacting and difficult.
In Jesus' parable in Luke 19:11-27, did not the man given one mina complain something similar to this when asked what he had gained with it? "Master, here is your mina, which I have kept put away in a handkerchief. For I feared you, because you are an austere man. You collect what you did not deposit, and reap what you did not sow" (verses 20-21).
We must be prepared to put God first in all things. There will be times when this will be exceedingly difficult, especially if the surrender of a thing involves the sacrifice of someone or something deeply loved or desired. It can happen, but such occasions are quite rare.
It has been said that he who is unwilling to sacrifice everything for the cause of God is really willing to sacrifice nothing. Drawing back happens despite God's promise that every trial is measured to the exact specifications needed by the individual Christian. In I Corinthians 10:13, God promises to provide relief from every problem: "No temptation has overtaken you except such as is common to man; but God is faithful, who will not allow you to be tempted beyond what you are able, but with the temptation will also make the way of escape, that you may be able to bear it." The word-picture in Hebrews 10:39 portrays a person shrinking back from following through on the demands of faith. He is looking for an easy way out of some distasteful thing he does not wish to face. This eventually happens to us all.
A major appeal of the world's way is that it seems to be broader and easier. As Jesus says in Matthew 7:13, the easier, broader way it probably is - for a while. That deceptively effortless way draws the person ever-further from salvation, and he grows steadily weaker as he loses contact with God. The one who apostatizes thus permits himself to be drawn back.
The third step is taken when a person actually turns away. John 6:65-66 records such an occasion in Jesus' ministry: "And He said, 'Therefore I have said to you that no one can come to Me unless it has been granted to him by My Father.' From that time many of His disciples went back and walked with Him no more." In this poignant scene, Jesus watched people who may have been friends leave His entourage because they could not comprehend His teaching. He undoubtedly had spoken of things of an order far higher than they were accustomed to hearing, but rather than patiently facing it, as the apostles did, they simply gave up, proving themselves unfit for the Kingdom of God. Their loyalty could not stand the strain of what may have been merely a temporary misunderstanding. They had been followers, but apparently, they were seeking for something else.
By this stage, it is still not too late for a person to grab hold of himself and move forward, but the world's appeal has become almost overpowering. Spiritual decline has reached the tipping point, and he is in serious peril.
The fourth and final step backward is illustrated by Isaiah in the Old Testament: "But the word of the LORD was to them, 'Precept upon precept, precept upon precept, line upon line, line upon line, here a little, there a little.' That they might go and fall backward, and be broken and snared and caught" (Isaiah 28:13).
In examining the context carefully, we see that the people being described have reached the critical point where God's Word is falling on deaf ears. It is to them just jumbled noise. In New Testament terms, they had backslid beyond the reach of repentance and forgiveness. Here, the apostate reaches the point of no return; he has earned the Lake of Fire.
John W. Ritenbaugh
God's Power: Our Shield Against Apostasy