Devotions used for communion services typically come from the Bible and the passages talking about the meaning of communion. For example, Colossians 3:1-4 says that believers are to set their minds above and away from earthly things, and to remember they have died to rise in Christ. A devotion might remind believers to remember dedicating their lives to Christ as they partake of the bread representing Christ's body.
Another devotion for a communion service comes from Jeremiah 25:15-18. This verse illustrates God's "cup of wrath" meant for those who disobey him. This contrasts with the cup of Jesus' blood rendered on the cross. A devotion using these verses might point out the contrast between the two cups and the difference between the old Covenant and the New Testament.
Hebrews 10:19-22 talks about the blood of Jesus and the assurance of faith. The assurance of faith comes from the blood of Jesus, which is represented by the cup of Communion. The verses in 1 Peter 1:17-23 discuss Christians' belief that Christ shed his blood for them. A devotion surrounding these verses might point out just how precious to Christians the blood is that the wine or grape juice in the cup represents.