A man who is not born with the novel-writing gift has a troublesome time of it when he tries to build a novel. I know this from experience. He has no clear idea of his story; in fact he has no story. He merely has some people in his mind, and an incident or two, also a locality, and he trusts he can plunge those people into those incidents with interesting results.
The best way is to read it all every day from the start, correcting as you go along, then go on from where you stopped the day before. When it gets so long that you can't do this every day read back two or three chapters each day; then each week read it all from the start. That's how you make it all of one piece.
Easy reading is damn hard writing. But if it's right, it's easy. It's the other way round, too. If it's slovenly written, then it's hard to read. It doesn't give the reader what the careful writer can give the reader.