Fail, either Christ’s sacrifice was sufficient or it was not. It cannot be both.
Go read Colossians Chapter 1, Verse 24. Read it and meditate upon it.
Christ’s sacrifice was sufficient to open the gates of heaven - his sacrifice does not guarantee entry because we have free will. It can be both and has to be both - we must cooperate with Him with our works - this is not a free ride.
Also look at Matthew 7:21.