As a Christian, our thought life is one of the biggest obstacles to fully living our calling in Christ. It is not a sin to be tempted by our thoughts, but to dwell upon sinful thoughts and give in to their temptation. Christians, especially new Christians, struggle with not giving these thoughts credence and sometimes will entertain them. This internal struggle of not assuming responsibility for our thoughts, takes us down a path away from Christ and leads us into our old bad habits and decisions. Paul shares with us the battle that each Christian faces and the power we each have as followers of Christ.
"For though we walk in the flesh, we do not war according to the flesh. For the weapons of our warfare are not carnal but mighty in God for pulling down strongholds, casting down arguments and every high thing that exalts itself against the knowledge of God, bringing every thought into captivity to the obedience of Christ, and being ready to punish all disobedience when your obedience is fulfilled." (NKJV) 2 Corinthians 10:3-6
With the understanding that ultimately our Christian walk, and the difficulty there-in can revolve around our thought life, then it should make sense to strive daily to live in God's presence. Isaiah reminds us that those who keep God in their mind will have constant peace.
"You will guard him and keep him in perfect and constant peace whose mind [both its inclination and its character] is stayed on You, because he commits himself to You, leans on You, and hopes confidently in You." (Amplified Bible) Isaiah 26:3
The main reference for this posting is Brother Lawrence's The Practice of the Presence of God. I highly recommend you read it. It is a short, but focused book that discusses the understandings that Brother Lawrence came to for constantly living in God's presence. I wanted to take one of his letters and use it as an example of how he dealt with his thought and prayer life and how he felt God rewarded us for our perseverance.
Concerning wandering thoughts in prayer. (NOTE: quoted from the Authentic Edition, page numbers from the paperback edition)
YOU tell me nothing new: you are not the only one that is troubled with wandering thoughts. Our mind is extremely roving; but as the will is mistress of all our faculties, she must recall them, and carry them to GOD, as their last end.
When the mind, for want of being sufficiently reduced by recollection, at our first engaging in devotion, has contracted certain bad habits of wandering and dissipation, they are difficult to overcome, and commonly draw us, even against our wills, to the things of the earth.
I believe one remedy for this is, to confess our faults, and to humble ourselves before GOD. I do not advise you to use multiplicity of words in prayer; many words and long discourses being often the occasions of wandering: hold yourself in prayer before GOD, like a dumb or paralytic beggar at a rich man's gate: let it be your business to keep your mind in the presence of the LORD. If it sometimes wander, and withdraw itself from Him, do not much disquiet yourself for that; trouble and disquiet serve rather to distract the mind, than to re-collect it; the will must bring it back in tranquility; if you persevere in this manner, GOD will have pity on you.
One way to re-collect the mind easily in the time of prayer, and preserve it more in tranquility, is not to let it wander too far at other times: you should keep it strictly in the presence of GOD; and being accustomed to think of Him often, you will find it easy to keep your mind calm in the time of prayer, or at least to recall it from its wanderings.
I have told you already at large, in my former letters, of the advantages we may draw from this practice of the presence of GOD: let us set about it seriously and pray for one another. (46-47)
Brother Lawrence eloquently points out that both in daily life and in prayer, focusing on God will allow us to live in His presence and better communicate with Him and control our thoughts. A good summation of Brother Lawrence's Eighth Letter is this:
"We must do everything with great care, avoiding impetuous actions, which are evidence of a disordered spirit. God wants us to work gently, calmly, and lovingly with Him, asking Him, asking Him to accept our work. By this continual attention to God, we will resist the devil and cause him to flee (James 4:7)." (61-62)
As we struggle with our thought lives, keep in mind that prayer and focus on Godly things allows us to "resist the devil and cause him to flee." When we are right in our thought life, we can better serve our Lord and neighbor and not be distracted from our calling to serve others and share the Gospel. It is OUR responsibility to work on our relationship with God and to deal appropriately with the thoughts that we have. No one else is responsible for your choice to entertain sin: not the movie that you watched, or the book that you read, or anything else that you expose yourself to. My favorite line in the Act of Contrition is, "I firmly resolve, with the help of Thy grace, to sin no more, and to avoid the near occasion of sin. Amen." I pray always, asking God to help me avoid these temptations. In doing so, I am taking responsibility for my thought life. It is time to stop blaming other people or things for our failures and accept the grace and strength Christ gave us to live out our lives in His presence.
I usually close with my own prayer, but I wanted to use a devotion from Joyce Meyer's book, Starting Your Day Right: Devotions.
October 20 - Temptation Isn't Sin
In the day when I called, You answered Me; and You strengthened me with strength (might and inflexibility to temptation) in my inner self. Psalm 138:3
Temptation to do wrong can make you feel horrible. You may think, I shouldn't be going through this; I shouldn't be having a problem with this. But God taught me that temptation isn't sin; we sin when we give into temptation.
The Bible says temptation will come. It doesn't say, "Woe unto him by whose hand it comes" (see Matthew 17:7). Jesus told us to pray that we would not give into temptation when we are tempted (see Luke 22:40).
Psalm 105:4 is a great way to start your day. It says, "Seek, inquire of and for the Lord, and crave Him and His strength (His might and inflexibility to temptation); seek and require His face and His presence [continually] evermore."