There are a whole lot of "provided that"s and "if"s. You don't have a great command of the Scriptures, do you.
"Although you were formerly alienated and hostile in mind, engaged in evil deeds, yet he has now reconciled you in his fleshly body through death, in order to present you before Him holy and blameless and beyond reproach---IF indeed you CONTINUE in the faith firmly established and steadfast, and not moved away from the hope of the gospel that you have heard." (Colossians 1:21-23, NASB)
It is very clear that, once a person has accepted the free gift, they must continue to honor it and remain firmly established, not moving away from the hope of the Gospel. They CAN move away from it.
The context is not salvation, but being grounded and settled!
Colossians 1:23 If ye continue in the faith grounded and settled, and be not moved away from the hope of the gospel, which ye have heard, and which was preached to every creature which is under heaven; whereof I Paul am made a minister;
Paul is addressing saints in Colosse (Colossians 1:2 KJV): those who have faith in Christ Jesus (Colossians 1:4 KJV), who are complete in Christ (Colossians 2:10 KJV) to know of the hope that is laid up for them in heaven having heard before the word of the truth of the gospel (Colossians 1:4-5 KJV).
To be grounded and settled and be not moved away from the hope of the gospel is to to be filled with the knowledge of God’s will in all wisdom and spiritual understanding.
Colossians 1:9 For this cause we also, since the day we heard it, do not cease to pray for you, and to desire that ye might be filled with the knowledge of his will in all wisdom and spiritual understanding;
God’s will is that all men be saved, AND to come unto the knowledge of the truth!
1 Timothy 2:4 Who will have all men to be saved, and to come unto the knowledge of the truth.
Whereunto Paul was ordained a preacher, and an apostle, a teacher of the Gentiles in faith and verity (1 Timothy 2:7 KJV), a minister, according to the dispensation of God which was given to him for us, to fulfil the word of God (Colossians 1:26 KJV)
Colossians 1:26 Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints:
Colossians 1:27 To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory:
Colossians 1:28 Whom we preach, warning every man, and teaching every man in all wisdom; that we may present every man perfect in Christ Jesus:
Colossians 1:29 Whereunto I also labour, striving according to his working, which worketh in me mightily.
Get saved and get a clue by 1 Corinthians 2:13 KJV.