An apostle is one sent out as an official representative of Christ. Paul (see below) commonly used this term as a self-designation in the openings of his letters. See "The Apostles: Can There Be Apostles Today?" below. Lea says:
The term "apostle" is used in the New Testament in at least two senses. It can refer to a messenger (apostles) or a representative of a church (Phil 2:25), or it can describe God's chosen ambassador who is commanded to testify concerning the resurrection and to herald abroad the gospel (1 Cor 9:1-2). In the Pastorals, Paul used it in the latter sense.
"God our Savior" is a scriptural title for God (1 Tim. 2:3; 4:10; Tit. 1:3; 2:10; 3:4). But denoting that God is our savior does not negate that Jesus is too! (Acts 4:12; 2 Tim. 1:2; Tit. 1:4; 2:13; Heb. 9:28; 2 Pet. 1:1; Jude 1:21). Just because we say something about one person and not about another in the same sentence does not mean the comment is not true about both parties. Sentences are often written to define emphasis and not necessarily differences.
Christ Jesus is the basis for Christian hope (cf. Rom. 5:1-5) because he is the mediator of the covenant of grace (1 Tim. 2:5; cf. see below); he is the believers only salvation and only means of salvation in the world (Acts 4:12). Salvation (soteria) encompasses the total work of God by which he rescues the elect from the ruin, doom, and power of sin and bestows upon him the wealth of his grace encompassing eternal life, provision for abundant life now, and eternal glory (Eph. 1:3-10; 2:4-10; 1 Pet. 1:3-5; John 3:16, 36; 10:10). See chart at "Here is a trustworthy saying that deserves full acceptance - 1 Timothy 1:15" below.
Liefeld comments:
It is striking to realize that although the word "salvation" appears forty-six times in the New Testament and the word "save" 107 times, "Savior" occurs only twenty-four times. In Paul's letters it occurs only twice outside of the Pastorals (Eph. 5:23; Phil. 3:20), but ten times within them (1 Tim. 1:1; 2:3; 4:10; 2 Tim. 1:10; Titus 1:3, 4; 2:10, 13; 3:4, 6). Almost half of the appearances of this word in the New Testament, therefore, are in the Pastoral Letters. Such words give Paul's opening words to Timothy (and also those to Titus) a weight of authority and majesty.
apostle of Christ Jesus. Paul was not on his own mission promoting his own teachings (cf. 2 Cor 4:5). He opened his letters to the churches at Rome, Corinth, Ephesus, Colossae, in the region of Galatia and to Timothy and Titus with the designation, apostle. He was sent as a representative of Israel's Messiah, Jesus, to tell the 'good news' about the victory his life, death and resurrection effected for the kingdom and glory of Israel's God. In the Psalms (65:5; 68:19; 79:9; 85:4; cf. 1 Chr 16:35), Israel prayed to
God, our Savior for deliverance from her own sins and from the oppression of her enemies. Paul's commission was to tell the story about how the Savior of Israel became the Savior of all people (1 Tim 2:3; 4:10; Titus 1:3, 2:10; 3:4).