I agree,
James says (2:10) “Whoever keeps the whole law and yet stumbles at just one point is guilty of breaking all of it.”
I would say yes but,
The Bible also states that God will be just and fair in His punishment of sin and that on the day of judgment some sin will merit greater punishment than others (Matthew 11:22, 24; Luke 10:12, 14).
I believe 1 Cor 3:13-15
suggests venial sin and thus purgatory (but that is another topic). No man is perfect except Christ- There is no way of knowing every little sin we commit, and a slim chance of being repentant and asking for forgiveness of every little sun before we die. Therefore
1 Cor 3:13-15
3each man’s work will become evident; for the day will show it because it is to be revealed with fire, and the fire itself will test the quality of each man’s work.
14If any man’s work which he has built on it remains, he will receive a reward.
15If any man’s work is burned up, he will suffer loss; but he himself will be saved, yet so as through fire.
Also there are many scrictures and I would have to go look them up such as Rev. 21:7-8 Where specific types of sins will not make it into heaven.
"Those who conquer will inherit these things, and I will be their God and they will be my children.** But as for the cowardly, the faithless, the polluted, the murderers, the fornicators, the sorcerers, the idolaters, and all liars, their place will be in the lake that burns with fire and sulfur, which is the second death." [Rev. 21:7-8]
As a fromer baptist I always had a problem with Christians around me professing once saved always saved, who were involved in these sins which they managed to justify in some manner, and had no apparent intent of repenting and asking forgiveness. (I say apparent intent because no one can no anothers heart fully)