Perseverance of the Saints - the "P" in "T U L I P".
This fifth point of Calvinism is historically known as "Perseverance of the Saints" in the sense that the Saints will persevere and get to heaven.
"Once saved; always saved" or "Eternal Security" are other descriptions.

Another way of thinking of it, which I is a better description, is "Preservation of the Saints". God preserves us to heaven.

Ephesians 1: 13-14:
“In Him, you also, after listening to the message of truth, the gospel of your salvation--having also believed, you were sealed in Him with the Holy Spirit of promise, who is given as a pledge of our inheritance, with a view to the redemption of God's own possession, to the praise of His glory.”

If we are “sealed” by the Holy Spirit which is given to us as a “promise”, shouldn’t we trust and even exalt in “Perseverance of the Saints”?!!!

“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.” I Peter 1: 4-5
God reserves our salvation. God protects our salvation through His power!

2 Timothy 4: 18:
“The Lord will rescue me from every evil deed, and will bring me safely to His heavenly kingdom; to Him be the glory forever and ever. Amen.”

The golden chain of salvation in Romans 8:29-30:
“For those whom He foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brethren; and these whom He predestined, He also called; and these whom He called, He also justified; and these whom He justified, He also glorified.”

John 10:27-29:
"My sheep hear My voice, and I know them, and they follow Me;
and I give eternal life to them, and they will 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.”

It is not necessary for Jesus to say anything more than no one shall snatch us out of His hands. But, to pound this point, no, to smash any thought of the Arminian view of “falling from grace”, Jesus brings the Father into discussion and obliterates any thought of His sheep losing their salvation - “no one is able to snatch them out of the Father's hand” .

I John 5:11-13:
“And the testimony is this, that God has given us eternal life, and this life is in His Son. He who has the Son has the life; he who does not have the Son of God does not have the life. These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life.”

“Perseverance of the Saints” is written throughout Scripture, ‘so that you may know that you have eternal life.”

Although not all Arminians believe you can lose your salvation or fall from grace, it is the logical conclusion to their theology, particularly a logical conclusion to their points of "free will" and "obstructable grace".

“Perseverance of the Saints” is more consistent with Reformed doctrine which places 100% credit for salvation on God and all glory to God as compared to Arminians who place some credit for salvation on man, maybe 50%, maybe 1%, maybe credit for just the faith. Under such Arminian logic, if even 1% of what is required for salvation must be supplied by man, man could fail to provide that 1% or withdraw that 1% credit that he "controls" sometime during his life.