Can't you willingly sin and continue to sin since Christ has already paid the price for all your sins?

My mom loves me. She made a lot of sacrifices to ensure that I have a good life. I remember looking through our old photos one day — photos of birthday parties of uncles, aunts and cousins inclusive. She was wearing the same outfit in most of them. It dawned on me that she was wearing the same outfit because she could not afford to splurge on new ones. She put her five kids first. I’ve said and done some nasty things to her that I utterly regret. Sometimes, I catch myself cringing physically when I remember some of the things my teenage and young adult self said to her in anger. In all of that, she still loved and took care of me as best as she could. I want to make her happy. I delight in making her happy. Why on earth would I willingly do things to upset her?

How much more our Father in heaven who so loved us that He gave His own Son that we might have life?

Being in Christ entails having a loving Father — child dependency/relationship with God. This relationship comes about through the revelation of God's love for us, the full expression of which is revealed in what took place at the cross: God's righteousness demands that every sin be punished to the uttermost. The wages of sin is death. All have sinned. No matter how well we obeyed the law, were all destined for death (preceded by its symptoms of lack, depression, sickness — earthly ills, physical death and finally death in hell.) - 

"For no one can ever be made right with God by doing what the Law commands. The Law simply shows us how sinful we are." Romans 3:20.

At the cross, God's Love and Justice met: He punished our entire lifetime of sins in the body of His Son, Jesus Christ so that we might not perish but have everlasting life. Instead of living life in a downward spiral of sins that lead to death, including earthly ills and death in hell, we get to have life and life more abundant, all through His undeserved, unearned, unmerited favour- Grace.

Having this mentality of “What if I willingly sin” is a testament to not yet understanding, experiencing, knowing or believing God's love and the impact of His saving grace in our lives. I might as well ask: 

“Can I willingly do things that will sadden my mom and continue to do things to make her sad knowing that she is forced to forgive me…”

Being in Christ is a having a personal relationship with Him that those who are yet to experience can never fathom. This is why these kind of questions — can I willingly commit sin - and bickering among churchgoers over God and His Word or with non-believers about His existence is an effort in futility. See John 6:43-46 (MSG)—

"Jesus said, “Don’t bicker among yourselves over Me. You’re not in charge here. The Father who sent Me is in charge. He draws people to Me—that’s the only way you’ll ever come. Only then do I do My work, putting people together, setting them on their feet, ready for the End."

Instead of joining in the bickering or trying to understand the Word via human logic, tell/ask God about what's not clear to you. He always hears and answers the prayers of His children.

These kinds of “bickering" questions also make it look like God hates sin because He doesn't want the sinner to enjoy himself or because He doesn't want dirty sinners around Him. Not so. Jesus was very comfortable in the company of scummy tax collectors and notorious sinners who knew that they had no good in them; but the law-toting self-righteous Pharisees who did their best to keep the law and depended on it for righteousness…not so much. He called them "hypocrites" and "white-washed tombs." And many churchgoers are following their example today, depending on their arm of flesh (human effort at obedience)  to make them godly aka "be like God" when Christ died for this same purpose:

Isaiah prophesied of Christ's suffering for us in Isaiah 53. See the result of His decease which He accomplished for us in Isaiah 53:11-

"After He has suffered, He will see the light of life. And He will be satisfied. My godly servant will make many people godly because of what He will accomplish. He will be punished for their sins."

God hates sin because it destroys the sinner that He loves: steal and you just might get caught and go to prison. Commit fornication/adultery and you just might catch a disease or find yourself at the opposite end of a jealous husband or wife’s gun or acid attack. Let's not even begin to talk about the mental gymnastics required to co-ordinate these activities and the stress, anxiety and agonizing over the possibility of getting caught that follow when your victims and other people begin to get suspicious. Depression doesn't necessarily just befall a person in one day. It is the result of days, weeks, months or even years of nursing guilt, stress and anxiety. God hates sin because it destroys the sinner that He loves- like the cancer in a beloved child. So He sent His own Son to save us from our sins (Matthew 1:21.)

True believers do not want to sin - only by Grace are we this way. We also know that of ourselves, there is no good in anyone — nobody can keep a jot of the Law by human effort. We would all be wallowing in sins were it not for God's Grace in our lives. The faster every believer realises this, the better: God's word says human effort (the arm of flesh) will fail, is powerless and cannot: Romans 7:18-

"For I know that nothing good lives within the flesh of my fallen humanity. The longings to do what is right are within me, but will-power is not enough to accomplish it."

But as it was with Peter who thought Jesus was wrong when He told him about his upcoming denials, knew that he would never deny Jesus and swore to follow Him to prison and to death, pride in the arm of flesh (human effort) that will fail says: 

"No, I can. God must be wrong. I still have some good in me. I can keep the law and restrain myself from committing sin by my will-power.”

God hates sin because it destroys the sinner that He loves, much like how an oncologist dad hates the cancer in his beloved but terminally ill child. Of himself, the child is helpless against the cancer as mankind is helpless when it comes to living in triumph over sin and death through human effort. So what did God do? He gave up His own Son to bear our sins and die our death. For all who believe, Christ has excised the cancer of sin from within us — Colossians 2:11–

“When you came to Christ, you were “circumcised,” but not by a physical procedure. Christ performed a spiritual circumcision—the cutting away of your sinful nature.”

God doesn't stop there. In Christ, as we keep on seeing ourselves as He does — righteous by Christ's blood and in spite of our many imperfections — He continuously fills us with the Holy Spirit, the only “chemo” that transforms us to perfect wholeness, removing all the symptoms of sickness and other imperfections that linger as a result of the cancer of sin that was in us. His eyes burn at and destroy sin but radiate perfect love for the sinner, transforming us to wholeness. See 2 Corinthians 3:18 —

“But we all with unveiled face beholding as in a mirror the glory of the Lord are being transformed to the same image from glory to glory, just as by the Spirit of the Lord.”

Any other method of transformation of our physical actions to godliness is as useless as a person with HIV (sin nature) thinking that he can cure himself of the virus (sin nature) by  treating the tuberculosis and other diseases (acts of sin)  arising from his immunodeficiency. The virus (sin nature) has to go or else the sicknesses (sins) will multiply and person will still die despite all of his puny efforts at ridding himself of his sins.

The sin nature (inherited from Adam) is characterised by trying to be godly (be like God) through human effort at obedience. It's carriers might attend church but do not believe Romans 5:19- 

"By one man's disobedience many were made sinners, so also by one man's obedience many will be made righteous."

From the verse above, we see that committing acts of sin is not what makes a person a sinner. Adam's sin took care of that long before anybody could commit a single act of sin. Sinners produce sin. It's inevitable. Adam infected all of his descendants with this sin nature that makes one have no choice but produce sins and imperfection. 

The sin virus is no more in all who believe God's word in Romans 5:9-

"And there is still much more to say of His unfailing love for us! For through the blood of Jesus we have heard the powerful declaration, “You are now righteous in My sight.” And because of the sacrifice of Jesus, you will never experience the wrath of God."

When your believing is right, right living will follow. With the old man (sin nature inherited from Adam) gone and God's new "righteousness nature" now reigning in all who believe, all the symptoms of the sin virus will disappear naturally, just as a person cured of HIV and infused with "life abundant" will no longer produce symptoms of the viral infection. With time, what is on the outside of the sinner who believes will align with the work of the Holy Spirit within all who believe on the Lord Jesus Christ. By grace, we trust in Christ to transform us by His power working in us. Titus 2:14 says of Him:

"He gave His life to free us from every kind of sin, to cleanse us, and to make us His very own people, totally committed to doing good deeds."

 The arm of flesh will fail. Never trust yourself. Trust in Christ. This is how we who are in Christ GET TO live in triumph over sin and death:

"For the sin of this one man, Adam, caused death to rule over many. But even greater is God’s wonderful grace and His gift of righteousness, for all who receive it will live in triumph over sin and death through this one Man, Jesus Christ." Romans 5:17.