Until now, the word πίστις and the various Greek expressions with it have drawn tremendous scholarly attention from Pauline scholars. They attempted to define the Greek term πίστις in Paul’s usage from multiple angles. One of the recent attempts was done by a classicist Teresa Morgan. Morgan argued that Paul and NT writers based their use of the term πίστις upon its common social understanding of trust in relationship in 1CE. Responding to and independently from her, Pauline scholars produced books and articles to tackle Paul’s understanding of πίστις. Joining this scholarly conversation regarding πίστις, we therefore would like to explore in this paper Paul’s understanding of it with particular attention to its threefold meanings, rejecting the simplistic tendency to define the term uniformly throughout the whole body of his letters. First, the term πίστις means the believers’ positive acceptance of the salvation message in Jesus’ Gospel on the basis of their cognitive change of its evaluation. In this sense, πίστις means faith in the truth claim of Jesus’ Gospel, and reveals the believers’ personal confidence in God’s salvation accomplished by Jesus. Second, πίστις however means total trust in God, who initiated the salvation and accomplished it through his Son Jesus, and Jesus on the basis of their personal belief in the veracity of Jesus event. God proved his faithfulness toward his people by sending his Son to the world and sacrificing him. Through Jesus event transmitted by Paul’s Gospel, that is, through Jesus’ death and resurrection, the believers came to trust in the faithfulness of their God and their savior Jesus. And on the basis of their trust, they are able to enter into a new covenantal relationship with God. Finally, the believers’ change of mind toward and positive acceptance of God’s Gospel, and their trust in God and Jesus require them to show persistent obedience toward God. The πίστις in terms of continuous obedience becomes a new existential realm for the believers and a new life principle. The πίστις in this sense should continue to grow through various life temptations and trials, and should govern their life as the life principle. In this way, the term πίστις for Paul is a very dynamic one with multiple implications in it. This means that when we interpret Paul, we should not reduce the term πίστις to just one meaning and thereby, limit the dynamics of Pauline theology. Our understanding of Paul will be made proper when we pay attention to particular implications of this term in various contexts of Paul’s letters.