That is true! Especially seems to be true among Christians!
Well, to your credit, even though it is simple to trust in Jesus to be saved, there isn't a formula given and no prayer to be copied in the Bible. In fact, Jesus says,
You should not be surprised at my saying, ‘You must be born again.’ The wind blows wherever it pleases. You hear its sound, but you cannot tell where it comes from or where it is going. So it is with everyone born of the Spirit. John 3:7, 8
My personal experience was that I understood more the more I questioned my own salvation experience and studied the Bible about it. In fact, although I think I know when I was saved, it is possible that my understanding and true salvation came years later. I kept thinking that it doesn't hurt to ask again....and surprisingly, although I am much more solid in my faith, the turnings of my heart to look to Jesus as my Savior are still what leads my worship of Him each day. Only instead of asking for Him to save me, just in case He hadn't already done so, I tell Him thank you for the sacrifice He made for me.
And something else to think of too. As believers we continue to struggle against sin and we give into a variety of sins: unforgiveness toward others, angry outbursts, disrespect toward authority or people in general, laziness, pushiness and lots of other sins are all things I personally give in to. 1 John 1 is a passage that can really help with understanding how to deal with sin in the life of a believer:
First to notice is that it is that Jesus' blood continually cleanses us from sin. I personally interpret that as a cleansing positionally, that there is no eternal judgment for those sins:
But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin. 1 John 1:7
Soon after comes an often quoted verse on confessing our sins. My understanding of this is that confessing simply means agreeing with God on the matter. Literally, to say the same thing about current sin in my life that God says about it. So, if I'm struggling to forgive a friend, then I should own up to that struggle and tell God about it and say that it is wrong for me to be unforgiving and ask His help in the matter. The verse is 1 John 1:9:
If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
My understanding of the verse above is that confessing to God my failures restores me to a relational fellowship to God. I see this as separate from a positional relationship with God.
Positionally, as being sealed by His Holy Spirit, I belong to His family and sin does not affect that relationship. However, sin does affect the relational aspect, just as a disobedient kid can expect his dad to correct him or perhaps pull away from him for a while, but it doesn't affect the permanency of being in the family.
My understanding of this verse also is that the "If we confess" is better read in the greek as an ongoing action, almost like saying "Since we are confessing our sins" and the forgiveness then is given not because we confessed to get the forgiveness, but because we are in Jesus, God is justified to be forgiving all of our sins.
I have to say though, that it took me years to come to my understanding of 1 John 1.
Yes and no. I do believe that once one has been genuinely saved, there is nothing that can take away that eternal life they were give, and nothing that will remove the Holy Spirit from His sealing of them.
However, if someone is in a state of unbelief and they formerly believed, I would think it is likely that they never had believed, to use your words, in the "necessary" way. There are forms of "belief" that are true belief. Consider these words from John 2 showing a type of "belief" that did not result in salvation:
23 Now while he was in Jerusalem at the Passover Festival, many people saw the signs he was performing and believed in his name.24 But Jesus would not entrust himself to them, for he knew all people.25 He did not need any testimony about mankind, for he knew what was in each person.
The above passage doesn't say exactly what was wrong with their belief, but I suspect it might have something to do with what Jesus had a problem with a few chapters later, that they wanted the signs and not salvation from sin:
Jesus answered, “Very truly I tell you, you are looking for me, not because you saw the signs I performed but because you ate the loaves and had your fill. John 6:26
Although salvation is instantaneous, the process of an unbeliever coming to that saving faith can be a very long one. The Scriptures encourage unbelievers to seek these things out:
so that they should seek the Lord, in the hope that they might grope for Him and find Him, though He is not far from each one of us. Acts 17:27
Seek the LORD while He may be found; call on Him while He is near. Is 55:6
Today, if you hear his voice, do not harden your hearts. Hebrews 3:15
I do admit that there are a few verses in the Bible that do talk about those who fall away and sometimes it would appear as though they had actually been believers at one time.
