The invocation is the calling upon God at the opening of public worship—the act by which the assembly, at the beginning of the service, calls upon the name of the Lord, acknowledges His presence, and seeks His help and acceptance for the worship about to be offered. It is the worshipping church’s first address to God: a brief, reverent calling upon Him to be present with His people, to receive their worship, to assist them by His Spirit, and to bless the ordinances about to be administered. The invocation rests on the truth that worship is not a human work performed in our own strength, but a holy approach to God that requires His enabling grace; we cannot worship acceptably unless God draws near, accepts us in Christ, and helps us by His Spirit, and so we begin by calling upon Him. It often takes its words from Scripture—‘Our help is in the name of the LORD, who made heaven and earth’; ‘O LORD, open thou my lips, and my mouth shall shew forth thy praise’—and is closely joined to the call to worship, by which the people are summoned to worship, and the invocation, by which God is called upon to meet them. The invocation must be carefully distinguished from the unlawful ‘invocation of saints’—the Romish and Eastern practice of calling upon departed saints and angels in prayer—which is a corruption and a form of idolatry, for prayer and the calling upon a name in worship belong to God alone: ‘whosoever shall call upon the name of the Lord shall be saved.’ The true invocation calls upon God alone, in the name of Christ the one Mediator, by whom we have access to the Father. It expresses at the threshold of worship the dependence, reverence, and faith with which the whole service is to be conducted: the people come not presuming on their own worthiness or ability, but calling upon their God to receive them, help them, and meet with them, that their worship may be acceptable through Jesus Christ.