This verse belongs to the YHWH run, Proverbs 16:1–9.
Quick answer
Self-assessment always comes back clean, because the inspector and the suspect are the same man. The LORD's scale is the one that reads true, and it weighs the spirit, not the story.
Read both lines
Not "some ways" but all the ways of a man are pure in his own eyes: self-justification is the factory setting. The second line sets a different instrument on the table: "weighs" is merchant language, the honest balance this chapter says belongs to the LORD (16:11), and what goes on His scale is the motive under the deed. The book repeats the saying at 21:2 with "hearts" for "spirits"; the sages thought it worth hearing twice. The point is not that everyone is secretly vile. It is that your own verdict on your own motives is the reading you should trust least, and being weighed is only terrifying if the verdict on you is still out. For the one in Christ, it is not.
Related: Proverbs 21:2 · 1 Samuel 16:7 · 1 Corinthians 4:3–5
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.