Always the scriptures must be taken in whole context. Paul (if he wrote Hebrews) is not saying that we are saved by works. He is saying that we participate as partners with God in working out our own salvation. This is a big part of what sonship is all about. We cannot take the exercise of our wills Today out of the equation no matter what we believe God does and sees over the whole enchilada. What are we to do? Ignore every injunction in the New Testament- every warning? This would certainly be foolish. "Labor diligently to enter into his rest", "Today if you hear His voice, harden not your heart". Hebrews alone has many exhortations and warnings, Virtually every speaker in the Old Testament and New includes these warnings and consequences of ignoring them.
If we cannot trust the Word in relation to these things, what business do we have trusting the Word that we are saved by "grace through faith". None, actually.
The attempt to take all the weight off of one side of the balance simply causes seekers to be thrown up into the air. Our choices, and learning to exercise our will in union with his, cannot be taken out of the paradigm. It is discipleship. We trust and believe and obey- and part of our trusting is that he is calling forth our efforts(for it is God who is in you to will and to work of his good pleasure) and his grace is filling them(strengthened with might in our inner man by the Holy Spirit). In the exercise of walking it out we begin to grow in discernment as to whether we are "working in religious flesh and self-effort" or if "the Lord is working with us, confirming our works." But I am very sure this principle applies, As we reap we sow. If we do not press into the Lord with our wills, mortifying the deeds of the flesh, we will not know the difference between when we are "resting" and just "lazy"- because our senses will not be exercised to know the difference.
Jesus, who gave forth more warnings than anyone against complacency and the result of it says "Watch, and pray that you might not enter into temptation, for the spirit is willing and the flesh is weak".
I think however that the warnings are not in terms of being "tossed out as a bastard child". I think it concerns sonship, the rewards of the overcomers, the right to participate in the inheritance,
Heb 3:13-19 But encourage one another day after day, as long as it is still called "Today," so that none of you will be hardened by the deceitfulness of sin. (14) For we have become partakers of Christ, if we hold fast the beginning of our assurance firm until the end, (15) while it is said, "TODAY IF YOU HEAR HIS VOICE, DO NOT HARDEN YOUR HEARTS, AS WHEN THEY PROVOKED ME." (16) For who provoked Him when they had heard? Indeed, did not all those who came out of Egypt led by Moses? (17) And with whom was He angry for forty years? Was it not with those who sinned, whose bodies fell in the wilderness? (18) And to whom did He swear that they would not enter His rest, but to those who were disobedient? (19) So we see that they were not able to enter because of unbelief.
They were brought out, but unable to enter. The wilderness lies in between living in Adam (Egypt)and living in the inheritance of Christ(promise).
"To every one who believes he gave the right to become sons of God" (John 1)
"Every son while he is still a child, is no different than a slave and must be kept under tutors until the appointed time" (Gal 4)
If we are immature we have the adoption rights but we cannot work within the house because Dad don't give little ones the keys to the major equipment.
Stewardship is about growing incrementally into the inheritance. To the one who is faithful over little, more shall be given.
If we as disciples can become as focused on how to enter the inheritance and walk as mature sons Today, Now- as we are on the fine lines of the doctrines of the faith, wow. Who knows what might break forth?
Rev 21:7 He that overcometh shall inherit all things; and I will be his God, and he shall be my son.
I do think that is it is possible to so grieve the Holy Spirit that one can be required to enter through the fire into that which was meant to be entered, "by grace through faith". I also believe that there are certain things one can disqualify ones self for both now and in the age to come, by disobedience and neglect.