What About Hebrews 5:12-6:12?

Children vs. Maturity

The first thing the author of Hebrews does is contrast those who are children and those who are mature. He says that though by this time these Christians ought to be teachers but they need someone to teach them the basic principles of the oracles of God again. These oracles of God are considered to be the words from Scripture in general. 

They needed elementary Christian instruction (milk) and not deep spiritual nourishment (solid food) for everyone who lived on milk is unskilled in the word of righteousness since he was a child. Solid food was for the mature and for those who have their powers of discernment trained by constant practice to distinguish good from evil. In other words, the mature had their senses trained and had the ability to make moral decisions distinguishing good from evil.

Therefore, the Christians would leave the elementary doctrine of Christ and go on to maturity, not laying again a foundation of repentance from dead works and of faith toward God and of instructions about washings along with the laying on of hands and the resurrection of the dead and eternal judgment. In other words, it was time to move on from basic doctrine to deeper understanding of the Scriptures.

Impossible to Fall Away

The author of Hebrews then states it is impossible in the case of those who have once been enlightened, who have experienced the heavenly gift cognitively and emotionally, along with obtaining it and coming to know it and have shared in the Holy Spirit to have fallen away (or have failed to follow through on a commitment to Christ). It is also impossible for those who have experienced the goodness of the word of God and the powers of the age to come to have fallen away.

Another impossibility would be to restore those who have fallen away again to repentance. This is because they're crucifying once again the Son of God to their own harm and holding Him up to contempt (which means public disgrace).

Cultivated Land vs. Land Bearing Thorns

Hebrews's author mentions the land that has drunk the rain that often falls on it and produces for a crop useful for those for whose sake it's cultivated receives a blessing from God. 

However, if it bears thorns and thistles, it is worthless and near to being cursed and its end is to be burned. This is referring to a thorn-plant that would be found on cultivated land and harmful to the grain. It would be a sign of a neglected field that would be unqualified and not meet the test. 

Relating to Jesus and Parable of the Sower

This, in turn, relates to Jesus talking about thorns in the parable of the sower. Jesus mentioned that when the word is sown among thorns, people hear the word but the cares of the world along with the enticement and captivation of riches and desires for worldly things enter in and choke the word. This has to do with plants of which food and light cut off by weeds come together and choke the plant. Jesus relates this to worldly desires cutting off and choking the word making it unfruitful.

Better Things/God Not Unjust

Although the author of Hebrews and the Christians would speak in this way, in their case they feel sure of better things-things that belong to salvation.

God is not unjust so as to overlook their work and the love they have shown for His name in serving the saints as they did.

Desires of Each of Them

The author then states they desire for each of them to show the same earnestness and to have the full assurance of hope until the end, so that they wouldn't be sluggish but imitators of those who through faith and patience inherit the promises.