As we know, there are many different denominations, sects and cults, all calling themselves Christian and all claiming to know the truth.
The Truth that Jesus died and rose from the dead for sinners is the same in denominations, sects and as you call them cults. Anything outside this is not relevant and yet those sects and cults seem to try and divide as you do.
You'll probably be the first to say that not all of these groups are Christian. Why? Because in your eyes, they won't know the truth.
Christians are those who believe that Jesus is the Son of God, died for sins and rose from the dead. So born of the baptism of the Holy Spirit and truth. What else can define a Christian?
If they don't believe these things how can they be Christian, if they do the rest is immaterial.
How do you know that the reason the truth eluded you in other religions was because you weren't in the right denomination?
It is easy, God reveals himself in the Jewish and Christian religion. STILL waiting for him to turn up in the others.