Matthew 6:5-7 is speaking of prayer and things NOT to do in prayer!
5Also when you pray, you must not be like the hypocrites, for they love to pray standing in the synagogues and on the corners of the streets, that they may be seen by people. Truly I tell you, they have their reward in full already. 6But when you pray, go into your [most] private room, and, closing the door, pray to your Father, Who is in secret; and your Father, Who sees in secret, will reward you in the open. 7And when you pray, do not heap up phrases (multiply words, repeating the same ones over and over) as the Gentiles do, for they think they will be heard for their much speaking. AMP
The born again believer in Jesus of Nazareth has the same right and authority to speak the Word of God and to use the name of Jesus in prayer! We should be praying His Word, speaking His Word and declaring His Word! Do you know that the angels of God have been given instructions to minster FOR us? Look at Hebrews 1:14:
14 Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation? KJV
They minister for us, but they are ONLY moved by the Word of God! Psalm 103:20:
Who excel in strength, who do His word,Heeding the voice of His word. NKJV
So what are we to do? We are to speak His Word with faith, trust and confidence that the angels of God are ON IT! Amen! Pray, speak and declare with confidence! Here is Hillsong Live with a new song called "Stand In Awe":