By this we know love, because He laid down His life for us. And we also ought to lay down our lives for the brethren. But whoever has this world’s goods, and sees his brother in need, and shuts up his heart from him, how does the love of God abide in him? My little children, let us not love in word or in tongue, but in deed and in truth.—1 John 3:16-18
Paul said this in Philippians
Therefore, my beloved, as you have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling; for it is God who works in you both to will and to do for His good pleasure. Do all things without complaining and disputing, that you may become blameless and harmless, children of God without fault in the midst of a crooked and perverse generation, among whom you shine as lights in the world, holding fast the word of life, so that I may REJOICE in the day of Christ that I have not run in vain or labored in vain. Yes, and if I am being poured out as a drink offering on the sacrifice and service of your faith, I am glad and REJOICE with you all.—Philippians 2:12-18 (emphasis mine)
Paul truly understood the love of God and loved others in deed and in truth. He viewed his entire life as a drink offering, and here in Philippians 2 it was poured out on the sacrificial service of the Philippians. An attitude of joy accompanies any genuine, sacrificial Christian service. That became very evident to me as I read through the following verses connected with sacrificial service and the accompanying attitude of joy that followed. It is important to note that this joy isn’t drummed up, it is produced by the Holy Spirit as a believer lays down his own will and pours out his life in service to God.
always in every prayer of mine making request for you all with joy,—Philippians 1:4
What then? Only that in every way, whether in pretense or in truth, Christ is preached; and in this I rejoice, yes, and will rejoice.—Philippians 1:18
that your rejoicing for me may be more abundant in Jesus Christ by my coming to you again.—Philippians 1:26
Great is my boldness of speech toward you, great is my boasting on your behalf. I am filled with comfort. I am exceedingly joyful in all our tribulation.—2 Corinthians 7:4
I now rejoice in my sufferings for you, and fill up in my flesh what is lacking in the afflictions of Christ, for the sake of His body, which is the church,—Colossians 1:24
therefore, brethren, in all our affliction and distress we were comforted concerning you by your faith. For now we live, if you stand fast in the Lord.
For what thanks can we render to God for you, for all the joy with which we rejoice for your sake before our God,—1 Thessalonians 3:7-9
Living as Christ desires us to live brings joy! God has built blessings in to our sacrificial service in His name. This is helpful for me to understand and remember, because it encourages my faith in two ways. It stirs me toward good works and assures my heart before Him as I walk in the rewards that accompany this service. Joy is one of these rewards. His commandments are not burdensome. Our obedience to them reflect our love toward God and brings blessing. One of these blessings is joy.
looking unto Jesus, the author and finisher of our faith, who for the joy that was set before Him endured the cross, despising the shame, and has sat down at the right hand of the throne of God.—Hebrews 12:2
And let us consider one another in order to stir up love and good works,—Hebrews 10:24
Now may the God of hope fill you with all joy and peace in believing, that you may abound in hope by the power of the Holy Spirit.—Romans 15:13