Matthew 28:18, “And Jesus came and spake unto them, saying, ‘All power is given unto me in heaven and in earth.’” God gave Jesus power or authority when he proved faithful by dying on the cross. 

This is symbolically shown in Revelation 5:2-5, 7, 9, 12 (NKJV), “…‘Who is worthy to open the scroll and to loose its seals?’ And no one in heaven or on the earth or under the earth was able to open the scroll, or to look at it. So I wept much,… But one of the elders said to me, ‘Do not weep. Behold, the Lion of the tribe of Judah, the Root of David, has prevailed to open the scroll and to loose its seven seals.’  And I looked, and behold… a Lamb as though it had been slain,…Then He (Jesus) came and took the scroll out of the right hand of Him (God) who sat on the throne. …  And they sang a new song, saying: ‘You are worthy to take the scroll, And to open its seals; For You were slain, And have redeemed us to God by Your blood Out of every tribe and tongue and people and nation,’ … 12 saying with a loud voice: ‘Worthy is the Lamb who was slain to receive power and riches and wisdom, And strength and honor and glory and blessing!’”

However, our Father God always has the supreme power and authority. Jesus is also subject to God. 1 Corinthians 15:27-28 (NKJV), “…But when He (God) says ‘all things are put under Him (Christ),’ it is evident that He (God) who put all things under Him is excepted.  Now when all things are made subject to Him, then the Son Himself will also be subject to Him who put all things under Him, that God may be all in all.”