Two scriptures come to mind..one used by those who teach you can have salvation and lose it:
Hebrews 6:4 - 6
"For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, And have tasted the good word of God, and the powers of the world to come, If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame"
And those who teach that if you are saved you are saved and will know truly that you are if god disciplines you when you do fall.
Hebrews 12:5 - 8
"And ye have forgotten the exhortation which speaketh unto you as unto children, My son, despise not thou the chastening of the Lord, nor faint when thou art rebuked of him:
For whom the Lord loveth he chasteneth, and scourgeth every son whom he receiveth.
If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not?
But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons."
I know there are numerous verses that support both teachings and also refute them.
We deal with people who say a "sinners prayer" and then go on to live the rest of their life in sin, are never chastened by the Lord and die in sin..were they ever saved in the first place?
But the person who truly believed and received the LORD and follows him, if they fall will be permitted to sin for awhile but then God intervenes. It can be as simple as someone giving you a message and you hear it and realize your sin and repent. Or, it can be as serious as getting everything you have taken from you, being driven from your community, sent on a long faith journey with almost nothing and forced to rely on the LORD.
Being a Christian for almost 32 years now I have experienced both.
So I think it is only conditional based on how you received the LORD when you met him in the first place, because if God gave you the gift and you fully received it, you may falter later but if truly saved God isn't going to let you get very far. I can also tell you that in a prodigal son scenario, sometimes God will let you find out for yourself and live among the pigs for awhile, then wake up and return to Him.
But other times Father is going to go out hunting, completely destroy the pig farm (symbolically or literally) and bring you home...