Entering a relationship is like starting a long-term investment for retirement. 

You build a good and strong marriage over time. It's the small deposits that make a big difference over the years.

If you aren't making a lot of small deposits, then making one big deposit won't make any difference. It may actually hurt your relationship in the long run.

If you make too many withdrawals, you will end up overdrawn which can cause the relationship to end.

This doesn't mean you count. Counting is one of the worst things you can do in a relationship.

This means you make genuine deposits into your relationship and take a genuine interest in your partner to show your love.

RELATED: The One Habit Loving Couples Practice To Avoid Taking Each Other For Granted

Here are five simple investments you can make in your marriage every day that will keep you happily together forever:

1. Kiss, kiss, kiss

This is very simple but it's easy to get away from when you're in a long-term relationship. Kiss for at least six and a half seconds, twice a day. This is not a long time.

When you kiss for six and a half seconds, things in the brain begin to change.

Prepare for the kiss like you did in the beginning, which means having a mint on the way home from work. Your partner will appreciate this.

RELATED: Married Couples Who Actually Stay Together Do These 7 Things Every Single Year

2. Know at least one important thing about your partner's day before parting in the morning

It's important to talk to one another before leaving. Take a genuine interest in your partner's work, friends, and family. Stay positive, even if you don't agree with your partner.

Let your partner know that you're rooting for them when they give their next pitch to the big boss. Be excited when your partner tells you that they're having lunch with some friends they haven't seen in a while.

You want your partner to feel that you're on their side, and open, clear communication will help with that.

RELATED: 5 Questions The Best Husbands Ask Their Wives Every Day (Or At Least Every Week!)

3. Think fondly of your partner when you are not with them

It's easy to think of all the things your partner hasn't done for you, or what you don't like about your partner. Even if you aren't saying this to your partner, this sets the tone for the relationship. You will come across as having an attitude.

This will put your partner on the defense.

Instead, think of how wonderful that last kiss was. Think of when they helped out around the house, without you having to ask.

This list is endless, so add your own.

RELATED: 5 Sweet Gestures That Make Your Partner Feel Exceptionally Loved

4. Be appreciative of one another

This is one of those simple deposits that we often forget after being married for a while. Tell your partner how much you appreciate them.

Tell them you appreciate their smile and can't wait to see them after a long day at work. Make sure to let your partner know how much you appreciate that they listened to you while you vented about your job last night.

I know life can be stressful with work, house, and children. But, don't forget your partner in the process. Showing appreciation doesn't take much time, and it makes a big difference.

RELATED: The Small-But-Meaningful Signs That Indicate A Man Is Truly Committed

5. Plan a weekly date

It's important that you and your partner have time for yourselves, without any distractions. This means shutting off all electronic devices.

You can go out to your favorite restaurant, go for a hike, a baseball game, or have a date night at home (just make sure the children aren't around).

Prepare for the date the way you did when you first met. Talk about your relationship, ask questions and listen with interest and enthusiasm.

By doing this, you are prioritizing your relationship and setting a positive tone. The investment will pay off.

There you go, this list is rather simple. If you've gotten away from it, you aren't alone. Many couples get away from the simple stuff.

We live in a fast-paced world. The good news is, it's not too late to start. Add one of these small investments to your relationship today.

Then, keep going. You can also add your own and personalize it.

RELATED: The One Sign I See In My Practice That Indicates A Marriage Is Going To Last

Lianne Avila is a Marriage & Family Therapist helping couples who are looking to rebuild a close emotional connection and get their relationships back on track.