Apart from the choice of the person we want serve, the choice of a life partner in marriage is another basic choice that can affect a fellow's destiny either positively or negatively. A wrong choice in marriage may go above the choice to serve the Lord. Solomon chose to marry a lot of women from other nations and they influenced him to leave the Almighty God and serve idols.
The choice of a better half will go to a very huge extent in either strengthening or weakening a fellow's relationship with the Lord. Solomon didn't want to forget the Lord who had done place him in the position where he was, but his choice of wives caused him to err.
A lot of people make expensive mistakes due to the fact that they don't seek God's guidance. It doesn't matter how much you know, depending on the Lord in making a decision is a sign of meekness and humility. The Almighty God still chooses the right marriage partner for His people who are willing to trust and obey Him.
Judgment in Psalms 25:9 means decision-making or preference, so, it is saying the Lord will guide the humble person in making choices. Even if you have little knowledge in the aspect where you have to make a choice, you still need to look unto the Lord. Lot chose a city that he thought would be very good for his agriculture. He surveyed the land, checked its prospects, knew it would very helpful for agriculture, and thus, chose to relocate there.
His knowledge was good, but it was limited in the light of the fact that he didn't know what the future held for that land. The Lord eventually destroyed the land in the period he over-throw the land of Sodom and Gomorrah. There seems to be nothing wrong with Lot making a choice; however, his mistake was that he didn't ask the Lord's guidance. Relying majorly on one's knowledge can destroy such a fellow's destiny and lead to eternal damnation.
Ask the Lord to guide you and good Christian counseling before choosing a life partner. Don't choose by sight and human knowledge alone; the Lord's direction is key to making a good choice in all aspects of life.