Can One’s Salvation Be Given Up?

Now, we are under the Gospel of Grace, water baptism is no longer required.

I suggest you watch the video...
Jesus said..EXCEPT...
He also said you MUST...
Unless you are completely born again you cannot enter the kingdom of God.
Christ reign...
1Co_15:25 For he must reign, till he hath put all enemies under his feet.
HE MUST reign...(note: Paul wrote this to the Church particularly at corinth... Christ in heaven and the church is already propagating)
Where he will reign
Rev 11:15 And the seventh angel sounded; and there were great voices in heaven, saying, The kingdoms of this world are become the kingdoms of our Lord, and of his Christ; and he shall reign for ever and ever.

Then what happens after he reign.
1Co 15:28 And when all things shall be subdued unto him, then shall the Son also himself be subject unto him that put all things under him, that God may be all in all.

Rev 22:4 And they shall see his face; and his name shall be in their foreheads.
Rev 22:5 And there shall be no night there; and they need no candle, neither light of the sun; for the Lord God giveth them light: and they shall reign for ever and ever.

Jesus also said he was not sent but to the lost sheep of the house of Israel.

Grace is a charisma a gift of God that works in us and even though us. "I became a servant of this gospel by the gift of God's grace" (Eph3:7) We need to be cleansed by water and refined by fire. The literal baptism may not be any more necessary than the animal sacrifices were. But this still represents a work that God needs to do in our life. Even the living water that flows from the Temple of God in Heaven today. This is represented by the Hebrew letter mem. In English the letters M & W represents water that can cleanse us or devour us. As fire can cleanse and refine or destroy. Healing is in the water, in the river of life. The tree of life is planted beside this river and the water flows into the Crystal sea where the sand looks like crystal and even diamonds.

"Then the angel showed me a river of the water of life, as clear as crystal, flowing from the throne of God and of the Lamb down the middle of the main street of the city. On either side of the river stood a tree of life, producing twelve kinds of fruit and yielding a fresh crop for each month. And the leaves of the tree are for the healing of the nations. " (Rev 22:2)

BAPTISM WILL BE REQUIRED AND IS A MUST until we are completely born again

He indeed said that...
Mar 7:25 For a certain woman, whose young daughter had an unclean spirit, heard of him, and came and fell at his feet:
Mar 7:26 The woman was a Greek, a Syrophenician by nation; and she besought him that he would cast forth the devil out of her daughter.
Mar 7:27 But Jesus said unto her, Let the children first be filled: for it is not meet to take the children's bread, and to cast it unto the dogs.
Mar 7:28 And she answered and said unto him, Yes, Lord: yet the dogs under the table eat of the children's crumbs.
Mar 7:29 And he said unto her, For this saying go thy way; the devil is gone out of thy daughter.
The above shows that even in healing..Jesus the the children first be filled...
however because they were PARTLY blinded..we gentiles received that grace as well.
Rom 11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.

Jesus did...
EXCEPT a man be born of WATER and Spirit..he cannot enter the kingdom of God..
he also said...Ye MUST be born again...
please watch the video to understand baptism.

But when Christ Jesus raised Paul to reach to us, Paul said in 1 Corinthians 1:16-17

And I baptized also the household of Stephanas: besides, I know not whether I baptized any other. For Christ sent me not to baptize, but to preach the gospel: not with wisdom of words, lest the cross of Christ should be made of none effect.

If Christ Jesus wanted water baptism to be so critical to our salvation, why would Paul say that?

Born of water is the physical birth.

Did you not read what you posted..
Christ sent me not to baptize..but to preach the Gospel..

Although he was not sent to baptize..he did baptise some...does that mean hes disobeying Christ?

There are different gifts...some are tongues..some are miracles...some are healing...etc...
Paul was sent to preached to the gentiles...but that does not mean he was not preaching to the jews as well.

The context is about that there's an argument, they are probably comparing (who baptized who) thereby giving the credit to the baptizer instead of the death and resurrection of Christ.

Because Acts was a transitional period?

Again, my point is, if water baptism was that critical to salvation now, why would Paul ever say that?

I am not asking this question from a theological perspective, but instead from a matter of fact. I tend to lean towards yes, one can “Give up” their salvation.

Scripture states that salvation cannot be take from a believer, but there are passages that indicate that a person can essentially forgo this free gift of God. I have listed verses below that I believe can verify this concept:

Matthew 5:13
Matthew 3:10
Mark 4:1-20
Revaluation 3:14-19

If you agree or disagree, please feel to explain why.