Paul preached about Jesus who is completely reliable and worthy of trust. Paul preached Jesus who is always faithful. Only because of Jesus who is faithful, we can be faithful. Faith is the work of God. He works it in us through the Holy Spirit. Faith is the channel of grace through which we receive God’s grace. We are not saved because we are so good and just or because God saw that we would believe, but by faith alone, which He gave to us through His Spirit. We can be faithful because God is faithful! It is not our doing, our choice, but through the grace of the Lord alone.