Php 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:
Php 1:2 Grace be unto you, and peace, from God our Father, and from the Lord Jesus Christ.
Php 1:3 I thank my God upon every remembrance of you,
Php 1:4 Always in every prayer of mine for you all making request with joy,
Php 1:5 For your fellowship in the gospel from the first day until now;
Php 1:6 Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ:
Time after time in the Pauline Epistles we see Paul, by inspiration of the Holy Spirit, as he greets the churches use the phrase Grace be unto you and then peace. The order of these two words is significant. We have to experience God's grace through salvation before we can ever know the peace that God offers. We live in a world of turmoil and distress where there is very little peace, but God offers peace to those that will believe on the Lord Jesus Christ.
Paul was thankful to God on every remembrance of the church at Philippi. The church is a wonderful thing in the life of the believer. It is a means that God uses to edify us as believers and to encourage us to continue our walk with the Lord. It is a place where we gain strength for the spiritual battle ahead. It's where we bear one another's burdens. Paul was grateful for the place that the Philippian church held in his heart. Paul's continual prayer for the church was that they would continue in their fellowship in the Gospel. That is the true foundation that the church has for fellowship, the Gospel of the Lord Jesus Christ. If a church or person doesn't believe the Gospel we should have no fellowship with them.
Paul's confidence rested in the fact that Christ would continue to perform His work in the lives of the Christians of Philippi. When Christ saves us it is simply a starting point. Christ begins a work in our life to conform us to the image of the Lord Jesus Christ day by day as we walk with Him.