"Maranatha" is one of the oldest Christian prayers — preserved in Aramaic at the end of 1 Corinthians. Whether it means "Our Lord, come!" or "Our Lord has come," the word is a window into the earliest Christian worship.
"Abba" is the Aramaic word for "father" — the intimate, personal address Jesus used when praying to God. Three New Testament passages preserve the Aramaic word, and each one teaches us something about how the Holy Spirit teaches us to pray.