Let me try to explain Hebrews 6:4-6:
The person who has been enlightened by God and who has received the Holy Spirit, etc. - if this person falls away (leaves the Lord - "backslides", then it in impossible for him/her to be brought back to repentance as long as they are continuing to "crucify the Son of God afresh" and are continuing to "put him to an open shame"
The "continuing" is based on the use of the Greek present participle
The person who has been enlightened by God and who has received the Holy Spirit, etc. - if this person falls away (leaves the Lord - "backslides", then it in impossible for him/her to be brought back to repentance as long as they are continuing to "crucify the Son of God afresh" and are continuing to "put him to an open shame"
The "continuing" is based on the use of the Greek present participle
[video=youtube;FZ4RjEqfXOg]https://www.youtube.com/watch?v=FZ4RjEqfXOg[/video]
Here is also a long version for those interested.
https://www.youtube.com/watch?v=ymCgHPu7Nz4