Does sanctification deliver us from the weaknesses of human nature?
No. We believe this experience does not deliver us from the infirmities, ignorance, and mistakes common to humankind, nor from the possibilities of further sin.
Catechism for the Global Methodist Church, question 74
1A prayer of David. Incline your ear, O LORD, and answer me, for I am afflicted and needy. 2Preserve my soul, for I am pious; save your servant. You are my God; the one who trusts in you. 3Be gracious to me, O my LORD, for I call to you all the day. 4Make glad the soul of your servant, for to you, O my LORD, I lift up my soul. 5For you, O my LORD, are pleasant and forgiving and abounding in kindness to all who call to you. 6Give ear, O LORD, to my prayer, and attend to the voice of my supplications. 7In the day of my distress I call to you, for you answer me. 8There is none like you among the gods, O my LORD, and there are no works like yours. 9All the nations that you have made shall come and bow down before your face, O my LORD, and they shall honor your name. 10For you are great and doing wonders; you alone are God. 11Teach me your way, O LORD; I will walk in your truth. Unite my heart to fear your name. 12I give thanks to you, O my LORD my God, with all my heart, and I will honor your name forever. 13For your kindness is great upon me, and you have rescued my soul from the lower Sheol. 14God, arrogant ones have arisen against me, and a congregation of ruthless ones has sought my soul, and they have not set you before them. 15But you, O my LORD, are a compassionate and gracious God, slow to anger and abounding in kindness and truth. 16Turn to me and be gracious to me; give your strength to your servant, and save the son of your maidservant. 17Make with me a sign for welfare, that those who hate me may see and be ashamed, because you, O LORD, have helped me and comforted me.
12Therefore let the one who thinks he stands take heed lest he fall.
7And because of the surpassing greatness of the revelations, therefore, in order that I might not become conceited, a thorn was given to me in the flesh, a messenger of Satan, to beat me, in order that I might not become conceited. 8Three times I pleaded with the Lord about this, that it might depart from me. 9And he said to me, My grace is sufficient for you, for power is made perfect in weakness. Therefore I will boast all the more gladly in my weaknesses, so that the power of Christ may rest upon me.
9And let us not grow weary of doing good, for in due time we will reap, if we do not give up.
12Take care, brothers, lest there be in any one of you an evil heart of unbelief in departing from the living God 13but encourage one another each day, as long as it is called 'today,' so that none of you may be hardened by the deceit of sin 14For we have become partakers of Christ, if indeed we hold the beginning of our confidence firm to the end 15while it is said, "Today, if you hear his voice, do not harden your hearts as in the rebellion"
26For if we go on sinning deliberately after receiving the knowledge of the truth, there no longer remains a sacrifice for sins, 27but a fearful expectation of judgment, and a fury of fire that will consume the adversaries. 28Anyone who has set aside the law of Moses dies without mercy on the evidence of two or three witnesses. 29How much worse punishment, do you think, will be deserved by the one who has trampled underfoot the Son of God, and has profaned the blood of the covenant by which he was sanctified, and has outraged the Spirit of grace? 30For we know him who said, Vengeance is mine; I will repay. And again, The Lord will judge his people. 31It is a fearful thing to fall into the hands of the living God. 32But recall the former days when, after you were enlightened, you endured a hard struggle with sufferings, 33sometimes being publicly exposed to reproach and affliction, and sometimes being partners with those thus treated. 34For you had compassion on those in prison, and you joyfully accepted the plundering of your property, since you knew that you yourselves had a better possession and an abiding one. 35Therefore do not throw away your confidence, which has a great reward. 36For you have need of endurance, so that when you have done the will of God you may receive what was promised. 37For yet a little while, and the coming one will come and will not delay; 38but my righteous one shall live by faith, and if he shrinks back, my soul has no pleasure in him. 39But we are not of those who shrink back and are destroyed, but of those who have faith and preserve their souls.
2I know your works and your labor and your perseverance, and that you are not able to bear evil ones, and you tested those who call themselves apostles and they are not, and you found them false. 3And you have perseverance and have borne up for my name, and you have not grown weary. 4But I have against you that you have left your first love. 5Remember therefore from where you have fallen, and repent, and do the first works; but if not, I come to you and will move your lampstand out from its place, unless you repent. 6But you have this, that you hate the works of the Nicolaitans, which I also hate. 7The one who has an ear, let him hear what the Spirit says to the assemblies. To the one who conquers I will give to him to eat from the wood of life, which is in the paradise of God.

This question guards the doctrine of entire sanctification against a misunderstanding Wesley spent his life correcting. The answer is quoted verbatim from Article XI of the Confession of Faith: "We believe this experience does not deliver us from the infirmities, ignorance, and mistakes common to man, nor from the possibilities of further sin." The article continues with the warning that the Christian "must continue on guard against spiritual pride and seek to gain victory over every temptation to sin." Christian perfection, in the church's teaching, is a perfection of love and never a perfection of knowledge, judgment, or bodily strength.
Infirmities, ignorance, and mistakes are the ordinary limits of creatures. Wesley named them as bodily weakness, slowness of understanding, and errors of judgment, none of which are sin properly so called, and none of which grace removes in this life. Paul's own experience is the catechism's first witness. He was given "a thorn... in the flesh," pleaded three times for its removal, and was told, "My grace is sufficient for you, for power is made perfect in weakness" (2 Corinthians 12:7-9). The sanctified apostle remained a weak man, and the weakness became the place where Christ's power rested. Psalm 86 is the prayer of a man who calls himself God's servant and still says, "I am afflicted and needy" (Psalm 86:1).
Nor from the possibilities of further sin follows from Article IX of the Confession, which says that even after regeneration "it is possible to depart from grace and fall into sin." The New Testament addresses its sternest warnings to believers. "Let the one who thinks he stands take heed lest he fall" (1 Corinthians 10:12). "Take care, brothers, lest there be in any one of you an evil heart of unbelief in departing from the living God" (Hebrews 3:12), and the remedy is mutual: "encourage one another each day, as long as it is called 'today'" (Hebrews 3:13). Hebrews 10 pleads, "do not throw away your confidence" (Hebrews 10:35). The church at Ephesus, praised for its works and perseverance, is told, "you have left your first love" (Revelation 2:4).
For a Methodist this teaching keeps holiness humble. A believer filled with love will still tire, misjudge, and err, and will still be tempted. Wesley's counsel was to keep on with the means of grace and to refuse discouragement: "let us not grow weary of doing good, for in due time we will reap, if we do not give up" (Galatians 6:9).