Do you believe when you get saved you are saved forever?

Ephesians 1 speaks about how God has predestined us before the foundation of the world-- and how when we first believe we are given a seal of ownership, of His Holy Spirit.
2 Corinthians 1:21-22 also says:
21And it is God who establishes us with you in Christ, and^(C) has anointed us, 22and who has also^(D) put his seal on us and^(E) given us his Spirit in our hearts as a guarantee.<sup>[a]

Jesus also says:</sup> John 10:29
My Father, who has given them to me, is greater than all, and no one is able to snatch them out of the Father’s hand.

I believe fully when we receive salvation in Jesus Christ we do not lose our salvation. One may fall into sin of course, but it is the Holy Spirit who convicts us and keeps us from falling away. I believe one who falls away and has no desire to return, one WITHOUT conviction was never saved to begin with- the parable of the sower in Luke is great in regards to this. The one who keeps on sinning was never truly regenerated by the Holy Spirit- in other words it was a false conversion. As I also believe as John 6:44 says that it is the Spirit who draws us to God, as no one can come to God on their own (Romans 3:10) This has a lot to do with it. The one who "believes" and takes root in God's word is the one whom the Holy Spirit has taken residence in. Without the Spirit one cannot be saved. Do you agree?

I said more on this in the demon and spirits category ( which is weird why this question would be there, but anyways....)

So if someone was to get saved and excepts Jesus Christ as his Lord and Savior and continues to live the way of the Bible or as close to it a possiable for years, then all of a sudden he starts to go through bad times or a change comes up in his life and he starts to sin worse then ever maybe he goes on a crime spree. And even murders someone. Is he still saved or does he lose his salvation until he repents again? This is a what if question.

God will not remove the Holy Spirit from you the first time
or even the second time but if that person does not eventually repent and
continues in sin, he will be lost forever and go to hell.
God will give you time to come back, but only for a time,
and then He shuts the door and then it is too late, even though you were once
saved and knew Him and belonged to Him.

2 Peter 2:20-21

For if, after they
have escaped the pollutions of the world through the knowledge of the Lord and
Savior Jesus Christ, they are again entangled in them and overcome, the latter
end is worse for them than the beginning. For it
would have been better for them not to have known the way of righteousness,
than having known it, to turn from the holy commandment delivered to them.

John, there are many
others like this one in the Bible but this is one of the more strongest ones
that proves that you can lose you salvation of you continue to sin with no
intention of repenting.

Escaping the
pollutions of the world by the knowledge of Jesus, means you are saved. Being entangled
in them and over come, means that you have become a backslider and are now into
sin.

The latter end is worse
for them than the beginning, means the
state that they are now in is worse that when they were lost and never know Him.
Even though they know God and were saved
and hade the Holy Spirit for a time, they chose to turn there backs on Him and
chose their sin instead. Now they have no excuse to say, “ Well I did not know
any better, I did not know God. “

For it
would have been better for them not to have known the way of righteousness,
than having known it, to turn from the holy commandment delivered to them,
means that they rejected Jesus’ Love and forgiveness by refusing to repent of
their sins and now they are going to have to pay for that for all eternity in
hell. Cense they know Jesus and still rejected Him and His love and forgiveness,
by refusing to repent of their sins, they will suffer a significantly greater
amount in hell than those who never knew God.

Look at what Jude
says about eternal security preachers in verse four.

I say this because
some godless teachers have wormed their way in among you, saying that after we
become Christians we can do just as we like without fear of God's punishment.
The fate of such people was written long ago, for they have turned against our
only Master and Lord, Jesus Christ. Jude 4

Look at 2 Peter 3:17
NIV version

There fore, dear
friends, since you already know this, be on your guard so that you may not be
carried away by the error of lawless men and (((((fall from your secure Position))).

John, here is a good
one I like a lot

Isaiah 7:9

(((If you do not stand firm in your faith, you will not stand at all.)))

I do have more but
that is enough for now.

I pray that these have convinced you some.
Pray over these verse and truly ask God to tell you the true meaning of them. These
verse make it very hard for the eternal security preachers to dance around to
make them sound there way. Blessing in His Name.

Jesus said, that if a man puts his hand to the plow and looks back, he is not fit fir the Kingdom of Heaven. This simply means that if you start out after God and return to sin, you will not enter Heaven.

Paul talks a lot, especially in the epistles about, if you start the race you must be in to the end or you will not receive the prize.

Without Holiness, no one shall see the Lord.

Jesus told us to take up our cross DAILY and follow Him.

Every time the Israelites started to wander away from God, Judgement was brought upon them. When they were close to God they had nothing to worry about, but when they refused to return to Him and His ways after they had warnings from the Prophits, BAM, God would hit them with an invading army or some disease, or some sort of judgement.
God would not let any Israelite that was over the age of twenty when the spies went into the promised land, and only Joshua and Caleb came back with "we can do it, God has given us this land" Not one person over the age of twenty at that time besides them two and their imediate family was allowed into the Promised Land. This was because they had turned their backs on God, and is a type of the Church today.
Samson is another type of the Church. As long as He kept his Nazarite Vow (Holiness) he had Gods favor, but as soon as he broke the vow by cutting of his hair, he lost Gods favor, anointing, salvation. If he had not repented, he would have died as if he was a Philastine.
The Old Testament is full of types like this.

Stone