Once we understand the difference between "sin willfully" in Hebrews 10:26 referring to apostasy (specifically Jewish Christians reverting to Judaism where there remained no more sacrifice for sins), and all other willful sins, we can then understand that all other willful sins can be forgiven if truly repented of. This video explains how we shouldn't use the fact that God forgives willful sin as a license to sin. The apostle Paul had some strong words regarding this very subject in His letter to the church in Rome. He said that where sin abounds grace does much more abound. He then answers the question of someone who would misunderstand that statement and use it as a license to sin so that grace may abound. Paul's response in Romans 6:2 was "shall we continue in sin that grace may abound? God forbid, how shall we that are dead to sin, live any longer therein?" When we are born again, we become dead to sin through Jesus Christ. We are freed from sin and shouldn't continue to live in sin. If we continue to live in sin, the wages of sin is death. We are given victory over sin through Jesus Christ, but if we sin and truly repent we will be forgiven. However, if our heart is bent towards continuing in sin because we know God forgives sin, then this could ultimately lead to our defeat and destruction and it reveals that there is something off in our heart. Jesus came to save us from our sins. He didn't come to save us in our sins. We can live a life of victory above sin by God's grace through the Spirit, but we must yield our members as instruments of His righteousness. We must walk after the Spirit and not after the flesh because if we walk after the flesh we will suffer eternal death. We must strive according to His working in us and grow unto full spiritual maturity in Christ. Those who think they can be born again and remain a babe in Christ and live a lukewarm Christianity will not be saved unless they repent and walk by faith, growing spiritually.