First Timothy 3:1-7 and Titus 1:5-9 lay heavy emphasis on the moral character of pastors. Character development is a lifelong process of growing in virtue, which is another way of saying that it is a lifelong process of producing the fruit of the Holy Spirit (Gal. 5:22-23). How do you grow in virtue? By attending to the means of grace God has given for this purpose: gathering with the church for the ministries of Word and table, devoting yourself to anchor points of daily Godward habits, cultivating a spirit of constant gratitude, walking in love toward others, and enduring both the blessings and sufferings of life with grace, humility, and dependence on the Lord. Character development happens all the time in all of life.
The list of resources gathered here can provide some guidance to you in this area. Disclaimer: My recommendation of a resource does not entail my personal endorsement of everything in it.
Carson, D.A. Memoirs of an Ordinary Pastor: The Life and Reflections of Tom Carson. Wheaton: Crossway, 2008.
Carson, D.A. Praying with Paul: A Call to Spiritual Reformation. Grand Rapids: Baker Academic, 2015.
Challies, Tim. Do More Better: A Practical Guide to Productivity. Hudson, OH: Cruciform Press, 2015.
Clear, James. Atomic Habits: An Easy & Proven Way to Build Good Habits & Break Bad Ones. New York: Avery Publishing, 2018.
Keller, Timothy. Prayer: Experiencing Awe and Intimacy with God. New York: Penguin Books, 2016.
Packer, J.I. Knowing God. Downers Grove: InterVarsity, 1993.
Peterson, Eugene. The Contemplative Pastor: Returning to the Art of Spiritual Direction. Grand Rapids: Eerdmans, 1993.
Phillips, Richard D. The Masculine Mandate: God’s Calling to Men. Sanford, FL: Reformation Trust, 2016.
Smith, James K.A. Desiring the Kingdom. Grand Rapids: Baker Academic, 2009.
Whitney, Donald. Praying the Bible. Wheaton: Crossway, 2015.
Whitney, Donald. Spiritual Disciplines for the Christian Life. Colorado Springs: NavPress, 2014.