If a person trust's Jesus to save the world they are not "in the dark". People will be judged for rejecting the "message" of Jesus - that He will "save the world".
"For God did not dispatch His Son into the world that he should be judging the world, but that the world may be saved through him..." ... "For even as, in Adam, all are dying, thus also, in Christ, shall all be made alive..." ... "God was in Christ, reconciling the world to Himself, not reckoning their offenses to them, and placing in us the word of reconciliation"(John 3:17 CLNT; 1 Corinthians 15:22 CLNT; 2 Corinthians 5:19)
The "word of reconciliation" is that salvation is a free gift to the world by the grace of God as a result of the shed blood of the Lamb of God who took away the sin of the world. It is a done deal, whether people in the Synagogue believe it or not.
"The next day John saw Jesus coming toward him and said, “Look! The Lamb of God who takes away the sin of the world!" (John 1:29)
Failing to obey all the laws and rituals of religious institutions will not be judged, however there will be a judgment that will take place based on the "message" and "truth" about our Savior Jesus, the Lamb of God.
Jesus is the "Savior of the world". I Savior is not one who offers to save or make an attempt to save, but is SUCCESSFUL in saving it.
"And we have gazed upon him, and are testifying that the Father has dispatched the Son, the Savior of the world..." ... "Faithful is the saying, and worthy of all welcome, that Christ Jesus came into the world to save sinners.." ... "we rely on the living God, Who is the Savior of all humanity, especially of believers. These things be charging and teaching." (1 John 4:14 CLNT; 1 Timothy 1:15 CLNT; 4:10-11 CLNT)
Thee day of judgment will reveal those who believed and shared this truth.
"Jesus is saying to them - I am the Way and the Truth and the Life. No one is coming to the Father except through me." (John 14:6 CLNT)
Those who work at teaching false doctrine, whether sincere or not, will see that work burned up regardless of how long they labored...
"For other foundation can no man lay beside that which is laid, which is Jesus Christ. Now if anyone is building on this foundation gold and silver, precious stones, wood, grass, straw, each man's work will become apparent, for the day will make it evident, for it is being revealed by fire. And the fire, it will be testing each one's work - what kind it is. If anyone's work will be remaining which he builds on it, he will get wages. If anyone's work shall be burned up, he will forfeit it, yet he shall be saved, yet thus, as through fire." (1 Corinthians 3:11 .-15)
Most Christians believe in Jesus but few will admit that Jesus is going to save everyone, preferring the fellowship and doctrine of the synagogue. Not much has changed over the past two thousand years.
"Many people did believe in him, including some of the Jewish leaders. But they wouldn't admit it for fear that the Pharisees would expel them from the synagogue. For they loved human praise more than the praise of God." (John 12:42-43 NLT)