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. (4:17)

--Philippians--

But ye know the proof of him, that, as a son with the father, he hath served with me in the gospel. (2:22)

--1 Timothy--

Unto Timothy, [my] own son in the faith: Grace, mercy, [and] peace, from God our Father and Jesus Christ our Lord. (1:2)

This charge I commit unto thee, son Timothy, according to the prophecies which went before on thee, that thou by them mightest war a good warfare; (1:18)

--2 Timothy--

To Timothy, [my] dearly beloved son: Grace, mercy, [and] peace, from God the Father and Christ Jesus our Lord. (1:2)

I thank God, whom I serve from [my] forefathers with pure conscience, that without ceasing I have remembrance of thee in my prayers night and day; (1:3)

Greatly desiring to see thee, being mindful of thy tears, that I may be filled with joy; (1:4)