Understanding John 16:24

This statement, from Jesus, officially endorses the idea of praying in His name: evoking His authority and His will in making requests known to God. That doesn't suggest God automatically grants every demand attached to the phrase "in the name of Jesus." Jesus makes this promise to those who pray "in" His name, not merely those who "use" His name. To pray "in" the name of Jesus means doing so in harmony with His will and His nature. A major part of living by faith is recognizing that not everything we want is what God wants for us.

~Dr. Robert L. Taylor, Bible Expositor; Teaching with God’s grace & power