In this world hatred is not dispelled by hatred; by love alone is hatred dispelled. This is an eternal law.

This eternal truth is from the Buddhist canon. 

Jesus said the same thing in fewer words.

Love your enemies.

or

Love one another.

There can be no argument that the three statements say the same thing about an eternal truth.

We all understand what we mean by eternal truth. Never changing, applicable to all human conditions, unconditional, from God.

The problem comes when we use the word "eternal" as an adjective for life. Just what is "eternal life?" The church has taken possession of this term and linked it to something that has to do with life beyond the grave. I don't think that the biblical writers had this in mind. 

Lutherans will be relevant in the 21st century when we admit that the Church of  Jesus Christ has almost nothing to say about life beyond the grave. We have a lot to say about those eternal truths which affect us here in God's Kingdom on earth. We have nothing to say about God's Kingdom in heaven. We trust that to God.