The Greek noun “θρησκεία”

Limited to Acts 26:5; Col. 2:18; Jas. 1:26-27, the Greek noun “threskeia” meant “worship” or “religion.”

Some religion can be “strict,” but still not pleasing to God (Acts 26:5).  Worship can also be directed to something other than the one true God (Col. 2:18).  James (1:26) said religion can be “vain.”  There is also “pure” religion (Jas. 1:27) which does please God.