Many marriages today -- even Christian ones -- seem to fall short all the time. Nowadays, it seems a whole lot easier to break and ruin a marriage than it is to keep a marriage intact.

Marriage takes and requires a lot of hard work, and it's very easy to break one apart. It all starts with priorities, obviously, and couples must always put God first in everything they do, their spouses second, their children third and themselves last.

Therein lies the rub -- the challenge of placing others before themselves, and this selfishness in the context of marriage can manifest in various ways. Here are four of the most common ways that marriages are laid to waste because of a lack of selflessness and sacrifice.

Mistake #1. Making your spouse your main source of happiness

It's true that a marriage is a man and woman's joy, but it should never be their main reason for happiness and satisfaction. The biggest mistake that spouses can ever make is thinking that they need their better half to be happy.

Romans 14:17 says, "For the kingdom of God is not a matter of eating and drinking but of righteousness and peace and joy in the Holy Spirit." God's presence and Spirit manifesting through our marriages is the true source of joy, and then the happiness that flows through marriage is just an add-on.

That's not to say that we should stop serving, surprising and expressing affection to one another, but we should stop relying on one another for contentment. Only God gives contentment, and the good things we experience with our spouses are just a consolation.

Mistake #2. Removing God from the center

In every argument and celebration, Jesus must be the center. Ecclesiastes 4:12 reminds us, "And though a man might prevail against one who is alone, two will withstand him—a threefold cord is not quickly broken."

When in financial hardship, emotional pain or spiritual challenge, as couples we are to look to God and remember Him as the strongest link in the marriage. Though we all as spouses do our part to cling to each other, we can only do so when both parties cling to God first.

Mistake #3. Limiting forgiveness

There is a very strong biblical emphasis on the need to forgive. Why? Because God knew from the beginning that man would be stupid and careless with His relationships. Colossians 3:13 says, "bearing with one another and, if one has a complaint against another, forgiving each other; as the Lord has forgiven you, so you also must forgive."

While others may argue that there are some instances, such as infidelity and abuse, that are unforgivable, be reminded that forgiveness does not necessarily mean second chances. Though we are to protect our own civil and moral welfare, the call is still strong to release bitterness and allow forgiveness to reign in all circumstances.

Mistake #4. Making trust and love conditional

I am extremely blessed to have a wife who trusts me based not on my capacity to remain true to my word. As much as I try my best to honor my wife and my God, I am a sinner beyond compare as we all are, and I need grace to get me by. Yes, I stay faithful, but there are times that I forget to lift the toilet seat, burn my wife's toast, scold my daughter too much and forget the keys in the car.

Despite those times, my wife trusts me still when I use the bathroom, drive the car and discipline my daughter. There is a need to perform yes, but love and trust come as a result of grace, not of performance.