Can you please explain Hebrews 6:4-6? Can we lose our salvation with no hope of repentance?
Hebrews 6:4-6 For it is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit, 5 and have tasted the good word of God and the powers of the age to come, 6 if they fall away, to renew them again to repentance, since they crucify again for themselves the Son of God, and put Him to an open shame.
When the twelve apostles were baptised with the Holy Spirit at Pentecost, one of the powers they received was to give Holy Spirit gifts to baptised believers by the laying on of their hands.
When Philip (who was not an apostle) converted and baptised some Samaritans, Peter and John travelled from Jerusalem to lay hands upon them. This is recorded in Acts 8.
Acts 8:5 Then Philip went down to the city of Samaria and preached Christ to them. 6 And the multitudes with one accord heeded the things spoken by Philip, hearing and seeing the miracles which he did. 7 For unclean spirits, crying with a loud voice, came out of many who were possessed; and many who were paralyzed and lame were healed. 8 And there was great joy in that city. 9 But there was a certain man called Simon, who previously practiced sorcery in the city and astonished the people of Samaria, claiming that he was someone great, 10 to whom they all gave heed, from the least to the greatest, saying, "This man is the great power of God." 11 And they heeded him because he had astonished them with his sorceries for a long time. 12 But when they believed Philip as he preached the things concerning the kingdom of God and the name of Jesus Christ, both men and women were baptized. 13 Then Simon himself also believed; and when he was baptized he continued with Philip, and was amazed, seeing the miracles and signs which were done. 14 Now when the apostles who were at Jerusalem heard that Samaria had received the word of God, they sent Peter and John to them, 15 who, when they had come down, prayed for them that they might receive the Holy Spirit. 16 For as yet He had fallen upon none of them. They had only been baptized in the name of the Lord Jesus. 17 Then they laid hands on them, and they received the Holy Spirit. 18 And when Simon saw that through the laying on of the apostles’ hands the Holy Spirit was given, he offered them money, 19 saying, "Give me this power also, that anyone on whom I lay hands may receive the Holy Spirit."
Those upon whom the apostles laid hands received different Holy Spirit powers as Paul explains:
1 Corinthians 12:27-31 Now you are the body of Christ, and members individually. 28 And God has appointed these in the church: first apostles, second prophets, third teachers, after that miracles, then gifts of healings, helps, administrations, varieties of tongues. 29 Are all apostles? Are all prophets? Are all teachers? Are all workers of miracles? 30 Do all have gifts of healings? Do all speak with tongues? Do all interpret? 31 But earnestly desire the best gifts…
Paul, after his conversion and appointment by Jesus as the ‘apostle to the gentiles’, received the same Holy Spirit powers as the 12.
Acts 19:6 And when Paul had laid hands on them, the Holy Spirit came upon them, and they spoke with tongues and prophesied.
With the death of the apostles Holy Spirit gifts could no longer be given.Today, these Holy Spirit powers are not available.
To return to Hebrews 6
V.4 For it is impossible for those who were once enlightened, (This means those who have understood the Gospel) and have tasted the heavenly gift, and have become partakers of the Holy Spirit, (This refers to the gift of the Holy Spirit received by the laying on of the apostles’ hands.)V.5 and have tasted the good word of God and the powers of the age to come, (They had experienced the gifts promised in the word of God. See Acts 2:17) and the powers of the age to come, (These powers are those which the faithful will receive in the ‘age to come’ i.e the kingdom of God when Christ returns to rule this world in righteousness.) V.6 if they fall away, to renew them again to repentance, since they crucify again for themselves the Son of God, and put Him to an open shame. (If after believing the Gospel, being baptised into Christ for the remission of their past sins, and receiving Holy Spirit powers, they then turn away from God and do evil in his sight, the first century Christians would not be able to repent and be forgiven a second time.)
This is based on the Lord's saying:
Luke 12:48 For everyone to whom much is given, from him much will be required; and to whom much has been committed, of him they will ask the more.
Because these Holy Spirit powers are not available today we cannot find ourselves in this position. While we have life we can repent and find forgiveness on the understanding that we will be forgiven as we forgive others:
Matthew 6:12 And forgive us our debts, As we forgive our debtors.
We can have confidence in God's forgiveness:
1 John 1:9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
I hope you find this helpful.