"Paul, an apostle of Christ Jesus according to the commandment of God our Savior, and of Christ Jesus, who is our hope, To Timothy, my true child in the faith: Grace, mercy and peace from God the Father and Christ Jesus our Lord." (1 Timothy 1:1-2)We never read Paul referring to himself as the "Apostle Paul" but always as "Paul, an apostle." Paul always referred to himself by his function within the body and never by title. Titles imply our position over the body while our function defines our relationship to the body. What is important is how we related to the body (what our function is) more than our position over the body (what our office is).
Jesus warned us of our use of titles when He commanded us, "But do not be called Rabbi; for One is your Teacher, and you are all brothers. Do not call anyone on earth your father; for One is your Father, He who is in heaven. Do not be called leaders; for One is your Leader, that is, Christ." (Matthew 23:8-10) Titles can be dangerous and can separate us from others in the body. Jesus warned us about giving titles to others and receiving titles for our self. Titles tend to lift up some over the body as if they were separate and above the body, obscuring the truth that we are all brothers and sisters. We should always endeavor to be no more than brothers and sisters to each other. Whenever we feel the necessity to give titles to others or require titles for ourselves we break down the bonds of brotherhood and set ourselves apart; which is a dangerous place to be.
Paul writes to Timothy as his "true son" using a particular Greek word that references one who was actually born of him rather than one who was adopted. In the book of Acts, we learn of when Paul first met Timothy, "Paul came also to Derbe and to Lystra. And a disciple was there, named Timothy, the son of a Jewish woman who was a believer, but his father was a Greek, and he was well spoken of by the brethren who were in Lystra and Iconium. Paul wanted this man to go with him..." (Acts 16:1-3) We know little of Timothy's natural father other than he was a Greek and an unbeliever. Paul took Timothy and raised him up in the things of God as if he was his own natural born son. Their relationship was special and transformative in Timothy's life. Latter on, Paul would write of Timothy, "But I hope in the Lord Jesus to send Timothy to you shortly, so that I also may be encouraged when I learn of your condition. For I have no one else of kindred spirit who will genuinely be concerned for your welfare." (Philippians 2:19-20) Paul's relationship with Timothy resulted in Paul's spirit being reproduced in Timothy. Timothy had become like Paul in his spirit, caring for others more than he cared for himself.
There are many today while having earthly fathers, lack fathers who can and will lead them into the things of God. This is not to condemn their earthly fathers, for many of them are doing the best they can, but one cannot lead another into what they themselves have not ventured into. It is important for mature men and women to help their younger brothers and sisters in their progress in the things of God; becoming mothers and fathers to those who need spiritual guidance and parenting; reproducing the good things of the Kingdom of God into the next generation of believers. You may not be a Paul and you may not have a Timothy, but you can still encourage, admonish, and lead others into all God has for them.