Knowing Him and doing His will are the same thing. WILL Jesus compared those who KNOW HIM to a wise man building His house on a Rock. Those who cry Lord, Lord, but never do God's will are the ones who hear His sayings and do not do them. Jesus said they are like the fool who built his house on sand. So if you love God and love your neighbours, along with calling Jesus Lord, you are a wise builder.
Actions speak louder than words.
And this word, Yet once more, signifieth the removing of those things that are shaken, as of things that are made, that those things which cannot be shaken may remain. Let brotherly love continue. All the world will shake in judgment. We can see how doing the Father's will means everything it is building a house on the Rock that cannot fall. Jesus said they are fools who build on sand, and their preparation is simply not good enough.