Foundation Scriptures:
But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, Meekness, temperance: against such there is no law.  Galatians 5:22-23 KJV
Rejoice in the Lord always [delight, gladden yourselves in Him]; again I say, Rejoice! 5 Let all men know and perceive and recognize your unselfishness (your considerateness, your forbearing spirit). The Lord is near [He is coming soon]. 6 Do not fret or have any anxiety about anything, but in every circumstance and in everything, by prayer and petition (definite requests), with thanksgiving, continue to make your wants known to God. 7 And God’s peace [shall be yours, that tranquil state of a soul assured of its salvation through Christ, and so fearing nothing from God and being content with its earthly lot of whatever sort that is, that peace] which transcends all understanding shall garrison and mount guard over your hearts and minds in Christ Jesus.  Philippians 4:4-7 AMPC

Joy is a Fruit of the Spirit.
As you allow the Spirit of God to do a work in your heart and life, the natural result will be that the fruit of the Spirit is manifested through you.
If you are full of God, you will be full of joy.
1 Chronicles 15:16 AMPC – “David told the chief Levites to appoint their brethren the singers with instruments of music—harps, lyres, and cymbals—to play loudly and lift up their voices with joy.”
When we praise God, we should do so with joy and rejoicing.

Joy has a Voice. If you are full of joy it will be evident to others around you.
Proverbs 15:13 AMPC – “A glad heart makes a cheerful countenance, but by sorrow of heart the spirit is broken.”
Proverbs 17:22 AMPC – “A happy heart is good medicine and a cheerful mind works healing, but a broken spirit dries up the bones.”
They will see joy on your countenance and they will hear joy in your voice and in your song of praise.
Psalm 33:3 AMPC – “Sing to Him a new song; play skillfully [on the strings] with a loud and joyful sound.”
Psalm 98:4 AMPC – “Make a joyful noise to the Lord, all the earth; break forth and sing for joy, yes, sing praises!”
Psalm 98:6 AMPC – “With trumpets and the sound of the horn make a joyful noise before the King, the Lord!”

Receive Your Salvation with Joy. Isaiah 12:1-6 KJV – “And in that day thou shalt say, O Lord, I will praise thee: though thou wast angry with me, thine anger is turned away, and thou comfortedst me. 2 Behold, God is my salvation; I will trust, and not be afraid: for the Lord Jehovah is my strength and my song; he also is become my salvation. 3 Therefore with joy shall ye draw water out of the wells of salvation. 4 And in that day shall ye say, Praise the Lord, call upon his name, declare his doings among the people, make mention that his name is exalted. 5 Sing unto the Lord; for he hath done excellent things: this is known in all the earth. 6 Cry out and shout, thou inhabitant of Zion: for great is the Holy One of Israel in the midst of thee.”
Verse 3 says: with joy we draw forth water from the wells of salvation.
In other words, you could say that joy is the bucket we use to draw forth the salvation that God has provided for us.
The Hebrew word translated here as “salvation” means deliverance, aid, victory, prosperity, health, help (-ing), salvation, save, saving (health), and welfare.
God has already handed salvation to us on a platter.
It is up to us to open our hearts to receive it.
Joy is a key to receiving from God that which we need.

True Joy Does Not Depend on Your Circumstances.
True joy is not manipulated by our circumstances, like happiness (which is dependent upon positive circumstances).
Even in the midst of a storm, joy is there, strongly anchoring us to the Word of God.
We are instructed by God to cast all of our cares upon Him.
1 Peter 5:7 AMPC – “Casting the whole of your care [all your anxieties, all your worries, all your concerns, once and for all] on Him, for He cares for you affectionately and cares about you watchfully.”
There is a rest and a joy for us as we allow Him to carry our burdens.
Philippians 4:4-7
When your faith is working for you, you rest in joy, knowing that God is bringing it to pass.
Why worry when God is in control!

Worship and Rejoicing Bring the Victory.
Psalm 5:11 AMPC – “But let all those who take refuge and put their trust in You rejoice; let them ever sing and shout for joy, because You make a covering over them and defend them; let those also who love Your name be joyful in You and be in high spirits.”
Psalm 35:9 AMPC – “Then I shall be joyful in the Lord; I shall rejoice in His deliverance.” 
Psalm 95:1-3 AMPC – “O come, let us sing to the Lord; let us make a joyful noise to the Rock of our salvation! 2 Let us come before His presence with thanksgiving; let us make a joyful noise to Him with songs of praise! 3 For the Lord is a great God, and a great King above all gods.” 
Psalm 138:5 AMPC – “Yes, they shall sing of the ways of the Lord and joyfully celebrate His mighty acts, for great is the glory of the Lord.”

The Lord Rejoices Over You.
Zephaniah 3:17 KJV – “The Lord thy God in the midst of thee is mighty; he will save, he will rejoice over thee with joy; he will rest in his love, he will joy over thee with singing.&rdquo
He loves you with an immense, incredible, everlasting love that cannot be stopped.
He will never stop loving you.
All you need is His love.
In His love is every answer to every question you could ever have.
He loves you so much that He sings joyfully over you.
You can rejoice over the fact that He loves you and that He rejoices over you!