Can we go to Heaven if we aren't fully sanctified during this life?
Can we go to Heaven if we aren't fully sanctified? The short answer to this is yes, we can. That's because during this life nobody is ever fully sanctified or fully holy. That state of perfection will only come after we die. The Bible does command us to be sanctified and the writer to the Hebrews says that "without sanctification, no man will see the Lord". However, that does not mean that we must achieve perfection. Indeed there is no particular level of sanctification that we need to achieve, even at a point lower than perfection. What does it all mean then? What level or standard do we have to achieve?
The answer is that there is no such arbitrary level or standard. We simply have to stay "on the Way". We have to continue in the process of being sanctified and pursuing holiness. Whilst ever we continue on the Way and are still in the process of being sanctified, bit by bit then, despite all our faults and mistakes, we are safe. We are secure because we are continuing. We are safe because we have not turned aside, or denied Jesus Christ, or abandoned Him, or betrayed Him, or ceased to follow Him. That is what matters.
Please let me re-emphasise as well, for the avoidance of doubt, that it is entirely possible to be, and to remain, on the Way, i.e. to be a real Christian, while making many ongoing mistakes. Making mistakes and falling into sin does not mean that you are no longer on the Way or that you have ceased to be saved. Far from it. We will all sin and we will all make mistakes and get bogged down at times. The question is whether we are still continuing to follow Jesus, despite all our faults and mistakes.
The Lord Jesus doesn't have any perfect or sinless followers. He doesn't expect to have any and He has never had any. What He does expect, and insist on, is our faithfulness. He demands that we do not desert Him or cease to follow Him. There is no question of Him ever deserting us. That is a certainty. We can be assured of that.
So, just keep on keeping on - for your whole life. Never turn away from Him. Never stop pursuing holiness or seeking to know and serve Jesus. Then, whenever you die, or whenever Jesus returns, He will find you faithfully walking along "the Way". He will then reward you for still being on the Way and for the fruit you have produced, even if others have gone ahead of you and have achieved more.
For the avoidance of doubt, sanctification is not what saves us, in the sense of taking away our guilt and giving us eternal life. We are saved in that sense when we are made righteous and forgiven due to being justified. That is the moment when we receive all of the righteousness of Jesus. We can never achieve that kind of righteousness for ourselves by the process of being sanctified. Sanctification and justification are two quite separate concepts. If you are still unclear as to the difference between them, please refer to chapters 10 (Jesus' death on the cross) and 12 (Salvation cannot be earned) again and see also chapter 22 (The three stages of salvation).