Contradiction with Psalm 30:11
Job 16:15 speaks of mourning with sackcloth and dust, while Psalm 30:11 speaks of turning mourning into dancing and replacing sackcloth with gladness.
Psalm 30:11: Thou hast turned for me my mourning into dancing: thou hast put off my sackcloth, and girded me with gladness;
Contradiction with Isaiah 61:3
Job 16:15 describes lament and distress, whereas Isaiah 61:3 offers beauty for ashes and joy for mourning.
Isaiah 61:3: To appoint unto them that mourn in Zion, to give unto them beauty for ashes, the oil of joy for mourning, the garment of praise for the spirit of heaviness; that they might be called trees of righteousness, the planting of the LORD, that he might be glorified.
Contradiction with Ecclesiastes 3:4
Job 16:15 indicates a time of mourning, but Ecclesiastes 3:4 states there is also a time to dance, representing joy.
Ecclesiastes 3:4: A time to weep, and a time to laugh; a time to mourn, and a time to dance;
Contradiction with Matthew 5:4
Job 16:15 shows expressed grief, while Matthew 5:4 promises comfort to those who mourn.
Matthew 5:4: Blessed [are] they that mourn: for they shall be comforted.
Contradiction with Isaiah 35:10
Job 16:15 conveys sorrow and suffering, yet Isaiah 35:10 foresees everlasting joy and freedom from sorrow.
Isaiah 35:10: And the ransomed of the LORD shall return, and come to Zion with songs and everlasting joy upon their heads: they shall obtain joy and gladness, and sorrow and sighing shall flee away.