Strengthened with all Might 
Who also declared unto us your love in the Spirit. For this cause we also, since the day we heard it, do not cease to pray for you, and to desire that ye might be filled with the knowledge of his will in all wisdom and spiritual understanding; That ye might walk worthy of the Lord unto all pleasing, being fruitful in every good work, and increasing in the knowledge of God; Strengthened with all might, according to his glorious power, unto all patience and longsuffering with joyfulness; Giving thanks unto the Father, which hath made us meet to be partakers of the inheritance of the saints in light: Who hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son: In whom we have redemption through his blood, even the forgiveness of sins: 
(Colossians 1:8-14)
It has been repeatedly shown on this web site1 from the word of God, that once we believe, we need to walk along that narrow path to reach the heavenly City. It is not enough "just to believe", nor is "once saved always saved" a reality, but a deception of Satan. 
Also many Christians believe that we can just ask to be strengthened spiritually in the name of Jesus Christ and it will be so. 
This is not Biblical and therefore not true. 
We see here the truth of the matter from the word that continues to come out from God through the anointing of the Holy Spirit; and we have this anointing because we were each anointed of the Holy Spirit when we were reborn. 
This truth is that while we walk worthy of the Lord, while we are obedient to His ordinances and wishes out of love for Him and mankind, and increase in the knowledge of Him by studying and doing to be approved - should we then need to be strengthened in His service, that He be glorified, we only need to ask and we shall receive. 
Mortify therefore your members which are upon the earth; fornication, uncleanness, inordinate affection, evil concupiscence, and covetousness, which is idolatry: For which things' sake the wrath of God cometh on the children of disobedience: In the which ye also walked some time, when ye lived in them. But now ye also put off all these; anger, wrath, malice, blasphemy, filthy communication out of your mouth. Lie not one to another, seeing that ye have put off the old man with his deeds; And have put on the new man, which is renewed in knowledge after the image of him that created him:
(Colossians 3:5-10)
Christians with power and strength: 
We give thanks to God always for you all, making mention of you in our prayers; Remembering without ceasing your work of faith, and labour of love, and patience of hope in our Lord Jesus Christ, in the sight of God and our Father; Knowing, brethren beloved, your election of God. For our gospel came not unto you in word only, but also in power, and in the Holy Ghost, and in much assurance; as ye know what manner of men we were among you for your sake. And ye became followers of us, and of the Lord, having received the word in much affliction, with joy of the Holy Ghost: So that ye were ensamples to all that believe in Macedonia and Achaia. For from you sounded out the word of the Lord not only in Macedonia and Achaia, but also in every place your faith to God-ward is spread abroad; so that we need not to speak any thing. 
(1 Thessalonians 1:2-8)
And whatsoever ye do, do it heartily, as to the Lord, and not unto men; Knowing that of the Lord ye shall receive the reward of the inheritance: for ye serve the Lord Christ. But he that doeth wrong shall receive for the wrong which he hath done: and there is no respect of persons. 
(Colossians 3:23-25) 
That ye would walk worthy of God, who hath called you unto his kingdom and glory. 
(1 Thessalonians 2:12)