Here's the opening verses to all of Paul's letters, where he constantly differentiates between Father God and the Son Jesus. Salutations from BOTH the Father AND the Son.

Romans 1

1 Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God,
2 (Which he had promised afore by his prophets in the holy scriptures,)
3 Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh;
4 And declared to be the Son of God with power, according to the spirit of holiness, by the resurrection from the dead:

1 Corinthians 1

1 Paul, called to be an apostle of Jesus Christ through the will of God, and Sosthenes our brother,
2 Unto the church of God which is at Corinth, to them that are sanctified in Christ Jesus, called to be saints, with all that in every place call upon the name of Jesus Christ our Lord, both their's and our's:
3 Grace be unto you, and peace, from God our Father, and from the Lord Jesus Christ.

2 Corinthians 1

1 Paul, an apostle of Jesus Christ by the will of God, and Timothy our brother, unto the church of God which is at Corinth, with all the saints which are in all Achaia:
2 Grace be to you and peace from God our Father, and from the Lord Jesus Christ.
3 Blessed be God, even the Father of our Lord Jesus Christ, the Father of mercies, and the God of all comfort;

Galations 1

1 Paul, an apostle, (not of men, neither by man, but by Jesus Christ, and God the Father, who raised him from the dead;)
2 And all the brethren which are with me, unto the churches of Galatia:
3 Grace be to you and peace from God the Father, and from our Lord Jesus Christ,
4 Who gave himself for our sins, that he might deliver us from this present evil world, according to the will of God and our Father:

Ephesians 1

1 Paul, an apostle of Jesus Christ by the will of God, to the saints which are at Ephesus, and to the faithful in Christ Jesus:
2 Grace be to you, and peace, from God our Father, and from the Lord Jesus Christ.
3 Blessed be the God and Father of our Lord Jesus Christ, who hath blessed us with all spiritual blessings in heavenly places in Christ:

Philippians 1

1 Paul and Timotheus, the servants of Jesus Christ, to all the saints in Christ Jesus which are at Philippi, with the bishops and deacons:
2 Grace be unto you, and peace, from God our Father, and from the Lord Jesus Christ.

Colossians 1

1 Paul, an apostle of Jesus Christ by the will of God, and Timotheus our brother,
2 To the saints and faithful brethren in Christ which are at Colosse: Grace be unto you, and peace, from God our Father and the Lord Jesus Christ.
3 We give thanks to God and the Father of our Lord Jesus Christ, praying always for you,

1 Thessalonians 1

1 Paul, and Silvanus, and Timotheus, unto the church of the Thessalonians which is in God the Father and in the Lord Jesus Christ: Grace be unto you, and peace, from God our Father, and the Lord Jesus Christ.

2 Thessalonians 1

1 Paul, and Silvanus, and Timotheus, unto the church of the Thessalonians in God our Father and the Lord Jesus Christ:
2 Grace unto you, and peace, from God our Father and the Lord Jesus Christ.

1 Timothy 1

1 Paul, an apostle of Jesus Christ by the commandment of God our Saviour, and Lord Jesus Christ, which is our hope;
2 Unto Timothy, my own son in the faith: Grace, mercy, and peace, from God our Father and Jesus Christ our Lord.

2 Timothy 1

1 Paul, an apostle of Jesus Christ by the will of God, according to the promise of life which is in Christ Jesus,
2 To Timothy, my dearly beloved son: Grace, mercy, and peace, from God the Father and Christ Jesus our Lord.

Titus 1

1 Paul, a servant of God, and an apostle of Jesus Christ, according to the faith of God's elect, and the acknowledging of the truth which is after godliness;
2 In hope of eternal life, which God, that cannot lie, promised before the world began;
3 But hath in due times manifested his word through preaching, which is committed unto me according to the commandment of God our Saviour;
4 To Titus, mine own son after the common faith: Grace, mercy, and peace, from God the Father and the Lord Jesus Christ our Saviour.

Philemon 1:3 Grace to you, and peace, from God our Father and the Lord Jesus Christ.