In I Samuel 15:3 God told King Saul to “go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and” etc. Evidently Saul thought he could make exception to God’s directive. He spared Agag (verse 9), and the best of the animals for sacrifice to God (verse 15). Of course we know the end of the story: Saul’s sin is called “rebellion” (verse 23), and the kingdom of Israel was “rent” from Saul that day (verse 28).
Sometimes God states a rule and then gives an exception. Luke 16:18 paired with Matthew 19:9 is a recognizable case of His doing that. But we don’t have the right to make an exception to one of God’s laws where He has not – like King Saul did.
For example Jerry Falwell correctly understood that passages like Exod 21:22-24 show abortion is wrong, but he said abortion was okay in the cases of rape and incest. Wasn’t Mr. Falwell making two exceptions where God hasn’t?
Consider how many Christians believe it is okay to swear if in a court of law, but Matt 5:34 says to “swear not at all” and James 5:12 says “swear not … by any oath.” Aren’t they also making an exception where God didn’t?
Some brethren who do believe in withdrawal won’t do it with family members – I guess because it is too difficult. But II Thess 3:6 teaches we are to withdraw from “every brother” that leaves the Lord. There is no exception given for family members or close friends.
Titus 2:5 instructs wives to be “keepers at home.” Many gospel preachers say this teaching should be followed as long as the family can afford it. But who has the right to take a command of God and change it into just a recommendation? The last I checked, Titus 2:5 does not state any exception to God’s “keepers at home” law.
God and His New Testament are our ultimate authority. We must submit to it as is – without watering it down by making our own exceptions to it (Heb 5:9).