This is the great and first commandment.
This is the first and great commandment.
This is the great (most important, principal) and first commandment.
This is the first and greatest commandment.
This is the greatest and first commandment.
This is the greatest and the first commandment.
And he said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind.
And a second like unto it is this, Thou shalt love thy neighbour as thyself.
If ye know these things, blessed are ye if ye do them.