The Bible commands us not to commit adultery. Decades ago, the definition of "adultery" was pretty simple: not engaging in a sexual relationship with a person who is not your spouse.

However, in today's tech world, modern conveniences like chats, phone calls and text messages add more complication to the question of marital infidelity.

Focus on the Family president Jim Daly said one of the most common questions they receive goes something like, "My spouse sent a romantic text message to another person, is that cheating?"

Sometimes people also ask if an "emotional affair' can be considered as cheating, Daly said.

"Beyond mere curiosity, these are actual real-life situations. Perhaps you've been wrestling with a version of it in your own marriage," Daly wrote in a blog.

Is sending a romantic text to a person other than your spouse considered cheating? Is being emotionally involved with another person considered unfaithfulness?

While addressing these issues is important, Daly focused on the bigger issue of why we enter marriage and vow to be committed to our spouse.

"Even more to the point, what motivates us to remain faithful to our wife or husband?" he said.

Daly discussed the difference between "sexual immorality" and "adultery," citing Hebrews 13:4, which mentions the two terms separately, indicating a distinction between them.

The verse says, "Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous."

He also said sexual immorality covers "any type of sexual expression" done outside the boundaries of marriage.

"Indeed, 'sexual immorality' is a broad term. Most often, when you see that phrase in the New Testament, it's a translation from the word porneia in the original language," Daly explained. "This word is also translated as 'fornication,' and it means 'a surrendering of sexual purity.'"

Regarding emotional affairs, Daly said such things often start when a person's heart "craves attention." He said husbands and wives should always strive to keep a healthy heart, as the Bible commands.

"Both the Old and New Testaments speak to the importance of maintaining a healthy heart (Proverbs 4:23, Psalm 51:10, Matthew 6:21). The heart is used as something of a metaphor for the inner life," he said.

He challenged couples to think of ways to build up their marriage and "lift up" their spouses through simple means, like going out on a surprise date or taking a walk after dinner.

Modern technology has created a lot of "gray areas" and has provided more ways for people to sin. Add to this the fact that the culture is changing rapidly, and "you have a recipe for moral confusion," Daly said. 

He gave a reminder that Satan is always looking for a way to "put a wedge" between husband and wife, to divide them and ruin the marriage.

"The enemy of our soul always wants to undermine," he said. "Don't let it happen."