Sentence:  The detractors of the Christian faith seem to revel in their "<WSD>discredit</WSD> of anything scientific concerning the basis of the belief that God is the causal Creator of man, yet offer no scientific 'proof that their criticisms are valid and their beliefs that there is no God, or first cause in creation, are provable by the evidence they present to the world. 
Meaning of the word marked with <WSD> tags:  Discrediting or disbelieving.