Everyone of us have people we love and want to make them happy but most of the time, things don't go as we expect and it might seriously hurt our relationship. Worst it could send the wrong message. By lover ones I don't just mean our biological family or friends, I mean anyone who you are close with and who respects you and with which you have a good relationship. Bellow, I will name some reasons we should express our affection to the people we love.

They need to know you care for them

They could think we don't care about them which is not good at all.
One of the common mistakes we all usually do is acting as if our loved ones will always be there. We are telling ourselves that there is still time to do it Only to drop the idea completely later because we are too deep in our work. Telling them this "I like you a lot" or a "thanks for always being there for me" can be enough to show you care for them and will be always thankful.

They are the only ones you can count on after yourself

Avoid unnecessary disputes with your loved ones. try to make compromises and avoid escalation. they are your most trusty allies and without doubt, the ones who know you the most, and whether you like it or not you will need them at some point in your life when you will be in a difficult situation. They will be the keys at these times. It's not by treating them like shit that you will get their favors.

They need to know you respect them even if you disagree

We all have different principles we don't want others to disregard. In this case, a lot of people really care about the way you address them, You'll have to use the right pronoun when talking to them. If they invite you somewhere, don't do something they won't like. Subjects like politics, religion, sexuality are very sensible and you should be careful with the way to approach them or not talk about it at all if they aren't comfortable with it, or else you might end up saying something that will destroy your relationship.

We won't be together forever.

In the end, you should follow your heart, what you really want. I'm sure none of us want to die or lose someone without them at least knowing what we really think of them.
Anyone can die at any time leaving behind their possession, loved ones and without accomplishing what they really wanted.

Spend time with them, it's not just about talking to them but showing through or action, that you really care for them. You can go on vacation together with them to spend time. When they are having a hard time maybe they lost someone, failed an exam you will be their support at that time. Help your loved ones in dears moments while giving your best. Make them smile while you still can talk to them.