There are many promises God has given, some to specific people under special circumstances and some to all His children. There are verses in the Bible that look like promises but we can understand from the context and from looking at other parts of the Bible that they are really not promises at all. For example, "Train up a child in the way he should go, Even when he is old he will not depart from it" (Pr.22:6) is not a promise but an exhortation for us to take parenting seriously. If we look around we can see children who have been brought up by godly parents going astray afterwards.
What happens when someone comes across "Believe in the Lord Jesus, and you will be saved, you and your household" (Ac.16:31)? Some people take this as a promise and assume that their children are guaranteed to be saved because they, the parents, have believed in Jesus. But then, without sharing the Gospel with the children and leading them to salvation, teaching them to pray and read and obey the Bible, and guiding them from early childhood to make the right decisions, many of these children become, at best, lukewarm nominal Christians. The Bible teaches us that salvation is not family-wise (or church-wise) but an individual experience.
In my middle thirties I heard one man saying the Lord had told him He would take care of his family as long as he took care of God's family. I took this as a general promise to me too! I began to occupy myself more with my 'ministry' and have less time for ministry to my family. Later I came to see how foolish this was, neglecting the responsibility for the family which God had entrusted to me while imagining that I was serving God!
When someone dies, many people comfort themselves thinking of some promise God had given them years ago, even when there is no evidence of that promise having made any difference to the person. Can we claim promises merely on a legal basis without fulfilling our part?
We have this strong evil tendency, to shirk our responsibilities and then to take cover under 'promises' of God. Certainly God has promised to take care of us, but because He has given us certain responsibilities and also abilities to carry them out, He will not interfere with our choices. It will be foolish for us to make all kinds of wrong choices and do wrong things and then 'claim' God's promises to cover them.
This tendency is one reason why the false preaching of hypergrace is attractive to many people. That gives them the impression that since it is 'all by grace' God will work out all things well for them even though they are not doing many things right! It is absolutely true that salvation is by God's undeserved favour towards us (Ep.2:8,9). None of us can be good enough or do good to earn it by works. But can we receive forgiveness if we don't admit our sins and repent, e.g., and then live without obedience (Ro.1:5)? There is a response to grace that God wants from us.