People who call themselves followers of Christ or "Christians" and claim they are born again must believe certain things.  If they do not then they fail the test of faith.  They can claim they are born again all they want and "once saved, always saved" but if they fail the test of faith there is no eternal security.  Only God knows who will be saved, from beginning to end, because of His foreknowledge and omniscience (Rom. 8:29, 1 Pet. 1:2).  God did not make an arbitrary judgment about who would be saved and who would not.  His Spirit is given to those He foreknew, when convicted of sin by His Holy Spirit, would choose to believe and commit themselves to Jesus Christ.  We are not God and we do not have His omniscience.  Therefore, according to Paul, we must be sure our belief system is in the right place once our eyes have been opened to the Truth.  I am not saying we do not have assurance of salvation, but our assurance comes not only because of His Atonement and promises of salvation but from our continuing in the Faith, which is always the Biblical criteria. Those who would be Bible teachers must teach according to the whole counsel of God's Word.  Let me be clear. There is only one way to salvation.  That is by grace alone through faith alone in Christ alone.  I will deal with a few of those issues following, but it is important to recognize that being saved is not just a matter of believing that Jesus lived, or that He was a man, or simply giving mental ascent to His existence in whatever form.