This is off topic, so I will not argue over it, but declare it just the once.
John 6:37. 'All that the Father gives Me will come to Me.........' 'Will come.' The Apostles had already come. All the elect of the Father were given to the Son in eternity (Ephesians 1:4-6) and the Lord Jesus will not lose one of them. They will come, stand before the throne and declare, 'salvation belongs [not to us but] to our God who sits upon the throne, and to the Lamb.'
'.......And the one who comes to Me I will by no means cast out.' Let no one say that he is not elect unless he has been up to heaven, had a look at the Book of Life and seen his name missing there. All others - thieves, swindlers, murderers, child molesters, Moslem suicide bombers, come to Christ! He will not cast you out.
However, coming to Christ means more than believing that there was such a person as Jesus of Nazareth who lived a long time ago and did a lot of good stuff. It means seeing yourself as a lost sinner, rightly under the condemnation of a thrice-holy God; turning away from your sins and laying hold of Christ as a drowning man might lay hold of a life-jacket, trusting in nothing else but His blood shed upon the cross to save you. Such a faith is God-given, the work of the Holy Spirit, that we should do the works that He prepared for us.
Therefore on the one hand, believers can never lose their salvation, and on the other hand they must and will persevere to the end. If they do not, it is because they never truly trusted in Christ.