That we might have joy (1 John 1:4):
This 1 John 1:4 verse is the only use of the word “joy” in John’s Epistles. However the blessing of joy is seen throughout his letter. Joy is a result of walking in a close place of fellowship or communion with our Lord. We as believers quote Philippians 4:13 often.
Philippians 4:13 ESV I can do all things through him who strengthens me.
Sometimes we get the caboose before the train engine. We know that according to John in his Epistle that walking in communion or fellowship with the Lord Jesus Christ brings about JOY.
We know that according to Nehemiah 8:10 that the JOY of the Lord is my STRENGTH.
Nehemiah 8:10 ESV Then he said to them, "Go your way. Eat the fat and drink sweet wine and send portions to anyone who has nothing ready, for this day is holy to our Lord. And do not be grieved, for the joy of the LORD is your strength."
We know that fellowship brings about joy, and joy brings about strength, and according to Philippians 4:13 that I can do all things through Him who strengthens me.
Then I can reason that the “all things” must start with fellowship or communion with our Lord. Fellowship produces joy, joy produces strength, and strength produces all things.