Notice that in both verses the verb form "to be" appears in the King James Version: in verse 1, "called to be an apostle," and in verse 7, "called to be saints." Neither "to be" is in the Greek text. While their insertion by the translators is not entirely wrong, they tend to give a misleading impression that can easily result in misunderstanding.
"To be" can give a person the impression of something resulting in the future or of something that must be earned. The Greek, however, does not imply either. In verse 1, Paul is clearly saying that his apostleship coincided with or was simultaneous with his calling! Acts 9:15-16 emphatically proves this. God had already determined what Paul would do at the time He called him. The same is true of our sainthood. The beloved of God are saints, and He loved us when He called us. He did not wait until later to begin loving us. In the same way, our sainthood began at our calling because God was already setting us apart.
The word translated "called" more specifically means "summoned." It does not imply "named" or "designated." It does not describe a name by which we are known but the thing we are summoned to be. The calling is our vocation, our work, and our work is to keep God's commandments and to witness for Him (Isaiah 43:11-12).
"Saint" and "holy" express the same general concept, though they entered the English from different languages. Both imply separation, consecration, or dedication. The common idea is "belonging to God." A saint, then, is one who has been summoned to be dedicated or consecrated as belonging to God.
Therefore, we are not our own but have been placed into an exclusive group. God has summoned us to glorify Him with our lives, and it is from this that the witness of Him shines forth. The glory of the witness arises entirely from a saint's striving for a purity of life that matches our Savior's. Without striving, the consecration derived from God's summons would not amount to a thing. What we see here is our tremendous privilege of being the called of God.
Amos 3:1-2 declares, "Hear this word that the LORD, has spoken against you, O children of Israel, against the whole family which I brought up from the land of Egypt, saying: 'You only have I known of all the families of the earth; therefore I will punish you for all your iniquities.'" The Israelites failed in their calling, but ours is exceedingly higher! Virtue, goodness, purity, righteousness, mercy, joy, and peace all express noble things we love to embrace, but they all go to naught unless we see who we are. For at the foundation of what we need to produce these wonderful qualities is holiness—what God has summoned us to be and do.
If we do not grasp the awesome privilege and purpose of this high calling, we will not aim high enough with our lives. We will not make the effort to produce because we will not see that this is our life. I Peter 4:17 admonishes us, "For the time has come for judgment to begin at the house of God; and if it begins with us first, what will be the end of those who do not obey the gospel of God?" Brethren, this is it for us! We will have no second chance to grab the brass ring!
Every branch of our armed forces has a special elite group like the Army Rangers or Navy Seals to which is given both honor and weighty responsibility. A similar civilian group would be the SWAT Team of a municipal police force. To be chosen as a member is an exceedingly great privilege. The implications of the Marine Corp's former advertising motto is appropriate if altered somewhat to apply to the called. About the Marines, it proclaims, "The few, the proud, the Marines." For us, it might say, "The few, the humbled, the called."
Far too many in the church of God have been deluded into believing in some slightly modified form of the worldly notion that all one has to do is to accept Christ. However, God is creating, and He has called us for the express purpose of giving us the opportunity to yield to His creative efforts. Yielding is the work of submitting to His will. This is how purity of life is produced; this is how character is built and how the witness is made.