To backslide, according to Merriam-Webster, is "to lapse morally or in the practice of religion."
Backsliding may mean that we now spend less time studying God's Word or praying. It may mean we meet less often with brothers and sisters in the Lord, or that we look for fewer opportunities to "do good unto all men, especially unto them who are of the household of faith." (Gal. 6:10) Or it may mean we don't try as hard to be "an example of the believers." (I Tim. 4:12) If this is true, we need to identify a cause.
The number of hours spent reading the Bible or serving others is not necessarily an indicator of our dedication to the Lord. At times, job requirements or specific responsibilities can keep us from giving time to Christian activities, and it's not due to lukewarmness. (Remember, that in your workday obligations you can still let your light shine. "Serve wholeheartedly, as if you were serving the Lord, not men."
The danger is in letting earthly responsibilities or attractions become more important than the Lord. "Be self controlled and alert. Your enemy the devil prowls around like a roaring lion looking for someone to devour." (I Pet. 5:8, NIV)
In the King James Bible, the word "backsliding" is found only in the Old Testament (Hosea 14:4). But the New Testament is filled with admonitions to be careful, persevering, and fervent in our devotion to the Lord, in order to avoid going "backwards" in our Christian walk.
If we realize we have become more interested in social activities and the beckoning world around us, or if we find we are developing a coolness toward Bible study, or becoming careless about sin, we need to seek immediate help from our Heavenly Father. Any joys we might experience from worldly activities or pleasures are short-lived and disappointing. We need to ask God to forgive us for seeking comfort and happiness through the things of this world and to ask Him to renew our trust in Him and His Son and in His precious promises of the Kingdom.
The book of Hosea deals in detail with Israel's backsliding and the sorrowful consequences of it. In the last chapter Hosea instructs Israel to plead with the LORD to take away their sin; then God answers, "I will heal their backsliding, I will love them freely; for mine anger is turned away from him,” Hosea 14:4. If we earnestly pray to God, He will heal our backsliding as well! The process of recovery teaches us to re-ignite our love for our Heavenly Father and again to renew our complete devotion to Him.