Something that God has been teaching me over and over in the last few weeks is that God's "calling" is upon every child of God. Not just some - but on every believer who has receieved Jesus into his/her heart.
When God calls us - He doesn't call us to a "task" - of 'doing' - He calls us to Himself. The overflow of that will result in an abundance of fruit in our lives that will be for His kingdom purposes! It's how our active faith participates to produce our good works.
2 Thessalonians 1:10-12
10 ...on the day He comes to be glorified in His holy people and to be marveled at among all those who have believed. This includes you, because you believed our testimony to you.
11 With this in mind, we constantly pray for you, that our God may count you worthy of His calling, and that by His power He may fulfill every good purpose of yours and every act prompted by your faith. 12 We pray this so that the name of our Lord Jesus may be glorified in you, and you in Him, according to the grace of our God and the Lord Jesus Christ.
John 15:4-5, 8
4 Remain in Me, and I will remain in you. No branch can bear fruit by itself; it must remain in the vine. Neither can you bear fruit unless you remain in Me.
5 "I am the vine; you are the branches. If a man remains in Me and I in him, he will bear much fruit; apart from Me you can do nothing.
8This is to My Father's glory, that you bear much fruit, showing yourselves to be My disciples. [emphasis mine]
Fruit - shows we belong to Jesus! It's the evidence of our close and abiding relationship with Him! The closer we get - the more fruit we bear!