Double-minded

     Double-mindedness is having faith but not being faithful. Scripture calls that wavering in the faith (Jas 1:6). Faith has metrics from no faith to perfect faith which is the faith of God. It takes only a little faith to be born-again but great faith to sacrifice oneself to the Lord. Abraham had great faith for his willingness to sacrifice his "only" son. Plotted against time, faith is not a straight line, nor even a curve, from one limit to the other. It varies from time to time and from day to day. The mountains are brought to you by God and the valleys by Satan. The slopes from valleys to mountains are wavers in the faith. Double-mindedness are those slopes, particularly the downward slopes!

Jas 1:8 A double minded man is unstable in all his ways. 4:8 Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye double minded.

     Constant faith is "steadfast faith":

1 Cor 15:58 Therefore, my beloved brethren, be ye stedfast, unmoveable, always abounding in the work of the Lord, forasmuch as ye know that your labour is not in vain in the Lord.

     "Steadfast faith" is one of assurance, and the people who have faith such as that are stable.  Temptations are tests of faith (1 Cor 10:13). Metastable Christians are those who when tempted "fall away" (Luke 8:13). Doubt pulls them down the slippery slopes to the valleys. Doubt is the lack of faith and is graphically the downward slopes from mountain peaks to valleys. The slope of those downward trends is "double-mindedness". Faith is still inherent but it is not practiced. Even Paul suffered double-mindedness:

Rom 7:15 For that which I do I allow not: for what I would, that do I not; but what I hate, that do I. 19 For the good that I would I do not: but the evil which I would not, that I do.

     Paul refers to this double-minded elsewhere:

Mat 26:41 Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak.

     Paul points out that entering into temptation makes one vulnerable for double-thought. He validates that the purpose of temptation is to test the faithful. Christians must overcome that metastable state which may lead to instability - the spiritual and mental states of chaos of those who have double-thoughts!
     What is double-mindedness? Serving two masters (Mat 6:24). Christians cannot serve God and themselves! Double-mindedness is thinking they can, and deceived into thinking it's alright. An example which comes to mind is my Christian friend who lusted after women at the same time he was worshiping God. He felt the spirit but at the same time the lust of the eyes and the flesh. That is double-mindedness.
     However, double-mindedness is not only the lusts men have but their own doctrinal errors: the pride of life, which is perhaps their view of the beginning as evolution when God says it is His creation. "God" is defined as one who creates. Some believe in a weak God who is incapable of creating! That is double-mindedness.
     Another example is believing "thou shalt not kill" (Exod 20:13) but insisting that abortion is acceptable. The ruses Satan uses to trick believers into that double-mindedness are two: (1) I can do what I want with my own body, and (2) the thing within me is not a person. Christians, you are not your own. Your bodies belong to God:

1 Cor 6:20 ...ye are not your own? For ye are bought with a price: therefore glorify God in your body...

     In response to ruse #2, that thing within you women is a person! God knew you in the womb (Jer 1:5). Furthermore John the Baptist leaped for joy upon recognizing Jesus in the womb (Luke 1:44). If a Christian believes their body belongs to themselves, and that it doesn't include life in the womb, they are double-minded and spiritually and emotionally unstable! Satan depends on unstable people doing their own will while claiming they are doing God's.  Satan is proud of his deception but God weeps at his creatures' foolishness!
     Double-minded has cures. Reading and listening to God's Word and prayer will keep potentially unstable Christians from the evil one:

Jas 4:3 Ye ask, and receive not, because ye ask amiss, that ye may consume it upon your lusts (double-minded). 4 Ye adulterers and adulteresses (unstable Christians), know ye not that the friendship of the world is enmity with God (serving two masters)? Whosoever therefore will be a friend of the world is the enemy of God (choosing wrong master). 5 Do ye think that the scripture saith in vain, The spirit that dwelleth in us lusteth to envy? 6 But he giveth more grace (example of double-mindedness). Wherefore he saith, God resisteth the proud, but giveth grace unto the humble (humbling those with the pride of life). 7 Submit yourselves therefore to God. Resist the devil, and he will flee from you. (the cure for double-mindedness). 8 Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye double minded (Let God purify the minds). 9 Be afflicted, and mourn, and weep: let your laughter be turned to mourning, and your joy to heaviness. 10 Humble yourselves in the sight of the Lord, and he shall lift you up (crucify the pride and God will stabilize your thinking).

     The underlining and parentheses are mine but the message is God's. If the Christian reader doesn't understand his or her mental instability, then perhaps unknown to either is their spiritual condition. The slope to Hell is slippery and even Christians can slide, and perhaps fall. Christians need to quit playing mental games with God and let His Spirit be the guide.