These teachings on prayer pertaining to Thanksgiving and Fasting are both necessary in order to have a prayer life with GOD where He accepts your prayers as you pray in His will. 
 
Thanksgiving in your prayer life is what keeps you centered in Jesus Christ for when you lose a thankful heart towards GOD, you’ll forget how good He has been. 
 
When GOD calls you to a fast, He’s saying that you’re "off course" and needs you to get back on track where you’re on fire for Him and will do whatever He tells you to. Included is a time of prayer that affords you the opportunity to reach out to GOD while making supplication with thanksgiving, and letting your requests be made known unto Him.