What a good question my friend . The answer is we cant if we have not been saved by HIM . I am living proof of this my friend .How do you preach the Good News about Jesus Christ as your Saviour unless you have been saved by Him? The fact that the Holy Spirit is in us always since salvation is proof that God has saved us at the calling of the gospel when we had first believed.
I too used to be able to tell a few folks , that you must believe in JESUS
however , My lifestyle was a total contradiction to how he lived and walked .
Just as the jews of sceva had tried to cast out demons in the name of JESUS ,they
too never had truly believed nor followed him and that DIDNT bode well for them
nor would it for me had i died in that state .
I rememeber one event very clear . I was still the marine corps
and living a deadly life in sin and loving the darkness . YEt
i had found me a conversation going on between an atheist
and another so called believer as i once was .
We both told that atheist YE have to believe in Christ to be saved or you will
perish at your end in a lake of fire . WHILE that indeed was true ,
had all three of us died that night , that athiest would have had him some
company in said lake of fire . MY heart was far from Christ . I never read that bible
never prayed and i love sin big time .
I was no example to that atheist , truth is the only example i was to him
was a bad example , NO matter that i did tell him the truth .
That poor man must have thought what hyprocrites . Cause he himself
had admitted to reading the bible at one time .
Yet , yet had the majority of these churches seen me back then
and a true christain had exposed my error , they would have attacked
the true christain claiming I was saved and to judge me .
YET I was not saved and my fruits PROVED that .