They have dealt treacherously against the Lord.
Believer, here is a sorrowful truth! Thou art the beloved of the Lord, redeemed by blood, called by grace, preserved in Christ Jesus, accepted in the Beloved, on thy way to heaven, and yet, "thou hast dealt treacherously" with God, thy best friend; treacherously with Jesus, whose thou art; treacherously with the Holy Spirit, by whom thou hast been quickened unto life eternal! How treacherous you have been in the matter of vows and promises. Do you remember the love of your espousals, that happy time - the springtide of your spiritual life?
Oh, how closely did you cling to your Master then! saying, "He shall never charge me with indifference; my feet shall never grow slow in the way of His service; I will not suffer my heart to wander after other loves; in Him is every store of sweetness ineffable. I give all up for my Lord Jesus' sake." Has it been so? Alas! if conscience speak, it will say, "He who promised so well has performed most ill. Prayer has oftentimes been slurred - it has been short, but not sweet; brief, but not fervent. Communion with Christ has been forgotten. Instead of a heavenly mind, there have been carnal cares, worldly vanities and thoughts of evil. Instead of service, there has been disobedience; instead of fervency, lukewarmness; instead of patience, petulance; instead of faith, confidence in an arm of flesh; and as a soldier of the cross there has been cowardice, disobedience, and desertion, to a very shameful degree." "Thou hast dealt treacherously."
Treachery to Jesus! what words shall be used in denouncing it? Words little avail: let our penitent thoughts execrate the sin which is so surely in us. Treacherous to Thy wounds, O Jesus! Forgive us, and let us not sin again! How shameful to be treacherous to Him who never forgets us, but who this day stands with our names engraven on His breastplate before the eternal throne.