Can we lose our salvation?
Yes. We believe, although we have experienced regeneration, it is possible to depart from grace and fall into sin.
Catechism for the Global Methodist Church, question 64
1I am the true vine, and my Father is the farmer. 2Every branch in me that does not bear fruit he takes away, and every branch that bears fruit he prunes so that it may bear more fruit. 3You are already clean because of the word that I have spoken to you. 4Abide in me, and I in you. As the branch cannot bear fruit by itself unless it abides in the vine, so neither can you unless you abide in me. 5I am the vine; you are the branches. The one who abides in me and I in him bears much fruit, for apart from me you can do nothing. 6If anyone does not abide in me, he is thrown away like a branch and withers; and they gather them and throw them into the fire, and they are burned.
27But I wear out my body and enslave it, lest after preaching to others I myself should become disqualified.
11These things happened to them as examples, and they were written for our admonition, upon whom the ends of the ages have come. 12Therefore let the one who thinks he stands take heed lest he fall.
3Then I fear that somehow, as the serpent deceived Eve by its craftiness, your minds might be corrupted away from the openness and the purity that are toward the Christ.
19You will say then, Branches were broken off in order that I might be grafted in. 20They were broken off because of unbelief, but you stand by faith. Do not be high-minded, but fear. 21For if God did not spare the natural branches, neither will he spare you. 22Behold therefore the kindness and the severity of God: severity toward those who have fallen, but kindness toward you, if you continue in the kindness; otherwise you also will be cut off.
4You were severed from Christ, you who are seeking to be justified by law; you have fallen away from grace.
8For now we live if you stand in the Lord.
18I set this charge before you, Timothy my child, in accordance with the prophecies previously made about you, so that by them you may fight the good fight. 19Holding faith and a good conscience, which some have rejected and so have suffered shipwreck in the faith. 20Among them are Hymenaeus and Alexander, whom I have handed over to Satan that they may be taught not to blaspheme.
1The Spirit expressly declares that in later times some will depart from the faith by paying attention to deceiving spirits and teachings of demons 2through the hypocrisy of lying persons whose own conscience has been seared
15For some have already turned aside after Satan.
1This then know: that harsh times will be present in the last days. 2For humans will be selfish, money-loving, braggarts, arrogant, blasphemous, disobedient to parents, ungrateful, and unholy. 3They will be unfeeling, irreconcilable, devilish, intemperate, brutal, and hating good. 4They will be traitors, reckless, puffed up, pleasure-loving rather than God-loving. 5They have a form of piety but have denied its power; turn away from these.
3For the time is coming when people will not endure sound teaching, but having itching ears they will accumulate for themselves teachers to suit their own passions 4and will turn away from listening to the truth and wander off into myths
1For this reason we must pay closer attention to the things we have heard, so that we do not drift away. 2For if the word spoken through angels proved firm, and every transgression and disobedience received its just recompense, 3how shall we escape if we neglect so great a salvation? It began to be spoken through the Lord and was confirmed to us by those who heard it, 4while God bore witness with signs and wonders and various powers and distributions of the Holy Spirit, according to his will.
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
1Therefore, leaving the word of the beginning about the Christ, let us be carried on to maturity, not laying again a foundation of repentance from dead works and of faith in God. 2Of instruction about baptisms, and of the laying on of hands, and of the resurrection of the dead, and of eternal judgment. 3And this we will do, if indeed God permits. 4For it is impossible for those once enlightened, having tasted also of the heavenly gift, and having become partakers of the Holy Spirit. 5And having tasted the good word of God and the powers of the age to come. 6And having fallen away, it is impossible to restore them again to repentance, since they are crucifying the Son of God for themselves afresh and putting him to open shame.
1But false prophets also arose among the people, just as false teachers will also arise among you, who will introduce destructive sects and deny the Master who bought them, bringing swift destruction upon themselves. 2And many will follow their debaucheries, and because of them the way of the truth will be blasphemed. 3And in greed they will exploit you with fabricated words. Their judgment pronounced long ago is not idle, and their destruction does not doze. 20For if, after they have escaped the defilements of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in them and overcome, the last state has become worse for them than the first. 21For it would have been better for them never to have known the way of righteousness than, after knowing it, to turn back from the holy commandment delivered to them.
17You therefore, beloved, knowing this beforehand, guard yourselves, lest being led away by the error of the lawless you fall from your own security.
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.
11I am coming quickly. Hold fast what you have, so that no one may take your crown.

The catechism now asks a question on which Methodists have always differed from their Reformed neighbors, and it answers with the third paragraph of Article IX of the Confession of Faith: "We believe, although we have experienced regeneration, it is possible to depart from grace and fall into sin." Article XII of the Articles of Religion, Of Sin After Justification, says the same: "After we have received the Holy Ghost, we may depart from grace given, and fall into sin."
The warnings come from every part of the New Testament, and they are addressed to believers. Jesus tells his disciples, "Abide in me, and I in you," and then, "If anyone does not abide in me, he is thrown away like a branch and withers" (John 15:4, 6). Paul writes, "let the one who thinks he stands take heed lest he fall" (1 Corinthians 10:12). He tells the Gentile believers in Rome, (Romans 11:20) They remain in God's kindness "if you continue in the kindness; otherwise you also will be cut off" (Romans 11:22). Hebrews urges its readers to "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 Peter describes people who "have escaped the defilements of the world" and are "again entangled in them and overcome" (2 Peter 2:20).
The church reads these warnings as real. A regenerate person retains the freedom that Article VII of the Confession of Faith describes, and freedom that can say yes to God can also turn away. This does not undo the assurance taught in question 60. The witness of the Spirit is a witness to a believer's present standing as a child of God; it says nothing about a future in which that believer refuses to abide. Wesley held the two together: a present, joyful confidence, and a sober watchfulness, "lest being led away by the error of the lawless you fall from your own security" (2 Peter 3:17).
For a Methodist this teaching is the reason the early societies met weekly to ask one another how their souls prospered. Hebrews gives the same prescription: "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" (Hebrews 3:13).