The Lord’s presence in our lives
Jesus says, "Surely I am with you always to the very end of the age" (Matthew 28). He also says, "Where two or three come together, there I am with them" (Matthew 18). What's the difference between these? Is the first talking about our individual relationship with Christ, and the second talking about Christ's relationship with the church? I know as omnipresent true God, Christ is always with me, even when I am not with another person. Can you please clarify the difference? Thanks.
It looks like you are heading in the right direction when it comes to providing a helpful understanding of these two promises of our Lord.
In Matthew 28, Jesus commissioned his church to teach God’s word and baptize people throughout the world. To comfort and strengthen his followers for this mission, Jesus promised to be with them always.
In Matthew 18, we see what the Christian church is all about. The Christian church consists of people, even as few as two or three, who are assembled in the Lord’s name. While God’s omnipresence penetrates every part of his creation, the Lord promises his special, gracious presence to Christians who gather in his name. Jesus’ promise in Matthew 18 is in the context of believers uniting together in prayer.
Put together, these passages remind you and me that we are not alone in this world. God is with us, and he has promised never to leave us or forsake us (Hebrews 13:5).