Hypocricy

"Hypocrites trade not with God upon the credit of Christ's love, blood, righteousness, and intercession, but upon the credit of their own prayers, tears, desires, and endeavours."
Thomas Brooks (1608 - 1680)

“Christian if you mourn for hypocrisy, yet find this sin so potent that you cannot get the mastery of it, go to Christ, Beg of him that he would exercise his kingly office in your soul, that he would subdue this sin and put it under the yoke. Beg of Christ to exercise spiritual surgery upon you. Desire him to lance your heart and cut out the rotten flesh, and that he would apply the medicine of his blood to heal you of your hypocrisy. Say that prayer of David often: ‘Let my heart be sound in they statutes’ (Psalm 119:80). ‘Lord, let me be anything rather than a hypocrite’ Two hearts will exclude from one heaven”
Thomas Watson

The hypocrite pretends goodness, but beneath a religious veneer is a malicious or deceitful heart ( Matt 22:15-18 ; cf. 1 Peter 2:1 ). Though hypocrites justify their religious activity, their hearts are not true to God ( Matthew 15:7-9 Matthew 15:18-19 ; cf. Isa 29:13-14 ). As in the Old Testament a discrepancy exists between outward conformity to religious ritual and the true state of their hearts ( Matt 23:25-30 ; contrast 5:8 ). Thus, the term "hypocrite" ( Matt 24:51 ) can occur as a synonym for "unfaithful/unbeliever." Such "hypocrites" hinder others from coming to Christ and even make converts to their godless lifestyle ( Matthew 23:13 Matthew 23:15 ; cf. Daniel 11:32 Daniel 11:34 ). Or they deceive others into doctrinal error ( 1 Tim 4:1-2 ). Thus hypocrisy is implied as one of the evidences of earthly or demonic wisdom ( James 3:13-17 ).

The absence of hypocrisy (genuine faith and sincere love from a pure heart) is a mark of godly character ( 1 Tim 1:5 ; 1 Timothy 2:5 1 Timothy 2:7 ; cf. Psalm 15:2-5 ; 24:3-5 ; 2 Col 6:6-7 ).
Baker's Evangelical Dictionary of Biblical Theology