1 Thessalonians 1:1: Paul, and Silvanus, and Timotheus, unto the church of the Thessalonians which is in God the Father and in the Lord Jesus Christ: Grace be unto you, and peace, from God our Father, and the Lord Jesus Christ. 2 We give thanks to God always for you all, making mention of you in our prayers; 3 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; 4 Knowing, brethren beloved, your election of God. 5 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. 6 And ye became followers of us, and of the Lord, having received the word in much affliction, with joy of the Holy Ghost: 7 So that ye were ensamples to all that believe in Macedonia and Achaia. 8 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. 9 For they themselves shew of us what manner of entering in we had unto you, and how ye turned to God from idols to serve the living and true God; 10 And to wait for his Son from heaven, whom he raised from the dead, even Jesus, which delivered us from the wrath to come.
The word idols in the passage is plural. Before we come to Christ we have many idols. For many of us these were our idols: our unbiblical churches, our unbiblical spiritual leaders, our habits, our feelings, our understanding, our bellies, our wealth, our pleasure, our position, our TV, our hobbies, our avocations, our parents, our heroes, etc.
Exodus 20:3: Thou shalt have no other gods before me.
Even after we are saved we still ignorantly place other things ahead of and above God. (Sometimes it is not so ignorant.) We need to turn from every idol. For us who have received Jesus, turning from idols should become a way of life, a habit and a growth process. Sometimes we only turn from one idol at a time. Sometimes we own learn about one idol at a time. As He reveals unto us things that are idols to our flesh that we didn*t know were idols, we need to turn from them all to the living and true God and serve Him. An idol for believers could be defined as anything that keeps us from serving Him
1 Samuel 7:3: And Samuel spake unto all the house of Israel, saying, If ye do return unto the LORD with all your hearts, then put away the strange gods and Ashtaroth from among you, and prepare your hearts unto the LORD, and serve him only: and he will deliver you out of the hand of the Philistines.
Matthew 4:10: Then saith Jesus unto him, Get thee hence, Satan: for it is written, Thou shalt worship the Lord thy God, and him only shalt thou serve.