1.God will save whom He will save. Yes, it is revealed to us in His word. Those who believe in the Lord Jesus Christ for their salvation,He will save. Those who never make that one time, non-meritorious(Acts 16:31) decision to believe, He will not save.
John 3:18~~
New American Standard Bible
"He who believes in Him is not judged; he who does not believe has been judged already, because he has not believed in the name of the only begotten Son of God.
2. He will remove salvation from whom He will remove salvation. That is not revealed to us in His word. In fact, the opposite is revealed to us.
and I give eternal life to them, and they shall never perish; and no one shall snatch them out of My hand. “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 and the Father are one.” (John 10:28-30)
The steps of a man are established by the Lord; And He delights in his way. When he falls, he shall not be hurled headlong; Because the Lord is the One who holds his hand. (Psalms 37:23-24)
There is therefore now no condemnation for those who are in Christ Jesus. (Romans 8:1 NASB)
For I am convinced that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, nor height, nor depth, nor any other created thing, shall be able to separate us from the love of God, which is in Christ Jesus our Lord. (Romans 8:38-39)
What then shall we say to these things? If God is for us, who is against us? He who did not spare His own Son, but delivered Him up for us all, how will He not also with Him freely give us all things? (Romans 8:31-32)
But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us. Much more then, having now been justified by His blood, we shall be saved from the wrath of God through Him. (Romans 5:8-9)
For you are all sons of God through faith in Christ Jesus. (Galatians 3:26)
Blessed be the God and Father of our Lord Jesus Christ, who according to His great mercy has caused us to be born again to a living hope through the resurrection of Jesus Christ from the dead, to obtain an inheritance which is imperishable and undefiled and will not fade away, reserved in heaven for you, who are protected by the power of God through faith for a salvation ready to be revealed in the last time. (1 Peter 1:3-5)
Now to him who is able to keep you from falling and to present you faultless before the presence of his glory blameless with great joy…” “To the only wise God our Savior through Jesus Christ our Lord, be glory now and forever. Amen.” (Jude 24-25)
Yes we can. He cannot lie.
Heb 6:18~~
New American Standard Bible
so that by two unchangeable things in which it is impossible for God to lie, we who have taken refuge would have strong encouragement to take hold of the hope set before us.
Titus 3:7~~
New American Standard Bible
so that being justified by His grace we would be made heirs according to the hope of eternal life.
He cannot revoke His Gift of eternal life.
Rom 11:29~~
New American Standard Bible
for the gifts and the calling of God are irrevocable.
Rom 6:23~~
New American Standard Bible
For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord.
He cannot be unjust.
Psalm 96:10~~
New American Standard Bible
Say among the nations, "The LORD reigns; Indeed, the world is firmly established, it will not be moved; He will judge the peoples with equity."
He would be UNJUST if salvation and His judgement on the peoples were not equal privilege and equal opportunity for ALL men. Anyone can believe on the Lord Jesus Christ and be saved. And if he changed it for just ONE man, he would be unjust and less than perfect in His justice.
He cannot be unrighteous.
Psalm 96:13~~
New American Standard Bible
Before the LORD, for He is coming, For He is coming to judge the earth. He will judge the world in righteousness And the peoples in His faithfulness.