The implicit promise of eternal life was given on condition of obedience in Genesis 2:17, but the tool used to deliver the promise was the tree of life described in Genesis and Revelation. God created a mechanism for salvation by the tree hewn for the construction of Noah's ark. God created a mechanism for salvation by the tree upon which Christ was crucified, and He constructed the church by that tree. The tree of life will provide the nutrition necessary for eternal life in Revelation 2:7. The ark was the tool of salvation from the floods. The church is the ark of salvation from the coming wrath. There was no life outside the ark. There is no grace outside the church. There is no life eternal outside the fruit of the tree of life. There is no resurrection without the tree of His crucifixion.