John
15:2 Every branch in me that beareth not fruit he taketh away: and every branch that beareth fruit, he purgeth it, that it may bring forth more fruit.
The religionist always agrues that: if a man truly believed, God will have him repents. If at last that man repents not, he never truly belived. However, in the scripture it saids, "Every branch in me...". For if that man were never being saved, how can he be a branch in Jesus? Even if he were once being saved, there is still a chance of being taken away.
The bible has also said:
18:24 But when the righteous turneth away from his righteousness, and committeth iniquity, and doeth according to all the abominations that the wicked man doeth, shall he live? All his righteousness that he hath done shall not be mentioned: in his trespass that he hath trespassed, and in his sin that he hath sinned, in them shall he die.
As the righteous turneth away from his righteousness, and committedth iniquity, will he die in sin. A man who were once saved, if he holds on to not, how shall he be saved?
There are also words from the bible, saying:
Exodus
32:33 And the LORD said unto Moses, Whosoever hath sinned against me, him will I blot out of my book.
If one were not saved, how will his name be in the book? If the name were blotted, how can he be saved?
Here we can clearly see that the book which names can be blotted is the Book of Life.
Revelation
3:5 He that overcometh, the same shall be clothed in white raiment; and I will not blot out his name out of the book of life, but I will confess his name before my Father, and before his angels.
From the above, we can see that salvation is needed to be kept with great effort. Because "the kingdom of heaven suffereth violence, and the violent take it by force. " May you try hard for the reward of having the heaven in your hands.