Luke 9:57 Now it happened as they journeyed on the road, that someone said to Him, “Lord, I will follow You wherever You go.” 58 And Jesus said to him, “Foxes have holes and birds of the air have nests, but the Son of Man has nowhere to lay His head.” 59 Then He said to another, “Follow Me.” But he said, “Lord, let me first go and bury my father.” 60 Jesus said to him, “Let the dead bury their own dead, but you go and preach the kingdom of God.” 61 And another also said, “Lord, I will follow You, but let me first go and bid them farewell who are at my house.” 62 But Jesus said to him, “No one, having put his hand to the plow, and looking back, is fit for the kingdom of God.”

There are many Christians but few disciples. To many Christians, Jesus is only a Savior. But Jesus is just the savior, but he wants to be Lord and Master.

Ephesians 1:1 Paul, an apostle of Jesus Christ by the will of God, To the saints who are in Ephesus, and faithful in Christ Jesus:

Colossians 1:2 To the saints and faithful brethren in Christ who are in Colosse: Grace to you and peace from God our Father and the Lord Jesus Christ.

Faithful men:

1Co 4:17 For this cause have I sent unto you Timotheus, who is my beloved son, and faithful in the Lord, who shall bring you into remembrance of my ways which be in Christ, as I teach every where in every church.

Eph 6:21 But that ye also may know my affairs, and how I do, Tychicus, a beloved brother and faithful minister in the Lord, shall make known to you all things:

Col 1:7 As ye also learned of Epaphras our dear fellowservant, who is for you a faithful minister of Christ;

Col 4:9 With Onesimus, a faithful and beloved brother, who is one of you. They shall make known unto you all things which are done here.

Early ages
Polycarp, Irenaeus, Origen, Eusebius, Augustine, Ambrose, Chrysostom, Jerome, Patrick,

Age of reformation
Martin Luther, Ulrich Zwingli, William Tyndale’s, Anabaptist, John Calvin, John Knox

Age of Revival
John Bunyan, William Penn, Isaac Watts, Jonathan Edwards, George Whitefield, John & Charles Wesley

Age of Progress
William Carey, Samuel Mills, J. N. Darby, George Mueller, Charles Finney’s, David Livingstone, Charles Spurgeon, D. L. Moody, Hudson Taylor

Age of Ideologies
Karl Barth , C. S. Lewis, Billy Graham