All means every living man and woman, including kings and all that are in authority. The “all men” in verse 4 would include kings and all that are in authority. Obviously, all kings and all that are in authority are not saved, but it is God’s will that they be saved.
1 Timothy 2
2 I exhort therefore, that, first of all, supplications, prayers, intercessions, and giving of thanks, be made for all men;
2 For kings, and for all that are in authority; that we may lead a quiet and peaceable life in all godliness and honesty.
3 For this is good and acceptable in the sight of God our Saviour;
4 Who will have all men to be saved, and to come unto the knowledge of the truth.