Calvin, among his other points, includes the point that Atonement is Limited; ie that Christ's death was sufficient for all but only effective for the elect.
What is the Biblical basis of this doctrine?
The Bible doesn't really say that Jesus' blood is sufficient for all, but it strongly suggests it. Jesus is the perfect lamb, and He give the power to become a son of God to " as many as received him." Surely the Lord God's blood is more than sufficient for the atonement of anyone He wishes to atone.
However, in regards to the Blood's efficacy, this is a matter of the election of God. It is not to say that the saving power of the Blood simply doesn't work for non-elect. That doesn't make sense. Jesus simply shed His blood for his elect (this is not to say that this was a simple process). This is probably what Calvin is talking about, since Unconditional Election is the basis for Limited Atonement. When Jesus took the cup he said,
"For this is my blood of the new testament, which is shed for many for the remission of sins." Matt. 26:28
Just like "many are called." Jesus' blood is "shed for many." Not all.