This is an easy one. We all have them, and its probably more difficult than any time in history to avoid them or put them out of our minds.
As has already been pointed out, there are religious idols of the heart, false doctrines etc, rituals we have difficulty letting go of. False doctrines are probably the worst idol of the heart according to Scripture. Jesus reserved his most wrathful indignation and condemnation for those scribes and Pharisees that were filled with hypocrisy and blasphemed God.
Riches was another idol of the heart that Jesus had a few things to say about.
Today we are tested more than any time in history. Those people whom Christ got so angry with in Mathew 23 didn't have anything like the stuff we have to contend with. Thousands of denominations, all saying they have the truth etc. Constantly bombarded with advertising for meterial things, imagery that attempts to lure us into sin, pressure to be socially and financially successful, the list is almost endless. As far as temptation is concerned the people in the time of Christ had it easy by comparison. Their lives were probably much harsher, probably more brutal etc, but they didn't have the temptation we are faced with almost the moment we open our eyes in the morning.
Mat 24:12 And because lawlessness will abound, the love of many will grow cold. 13 But he who endures to the end shall be saved.
Mark 13:13 And you will be hated by all for My name’s sake. But he who endures to the end shall be saved.
2 Thes 1:3 We are bound to thank God always for you, brethren, as it is fitting, because your faith grows exceedingly, and the love of every one of you all abounds toward each other, 4 so that we ourselves boast of you among the churches of God for your patience and faith in all your persecutions and tribulations that you endure, 5 which is manifest evidence of the righteous judgment of God, that you may be counted worthy of the kingdom of God, for which you also suffer;
2 Tim 2:1 You therefore, my son, be strong in the grace that is in Christ Jesus. 2 And the things that you have heard from me among many witnesses, commit these to faithful men who will be able to teach others also. 3 You therefore must endure[a] hardship as a good soldier of Jesus Christ. 4 No one engaged in warfare entangles himself with the affairs of this life, that he may please him who enlisted him as a soldier.
2 Tim 2:10 Therefore I endure all things for the sake of the elect, that they also may obtain the salvation which is in Christ Jesus with eternal glory.
11 This is a faithful saying: For if we died with Him, We shall also live with Him. 12 If we endure, We shall also reign with Him. If we deny Him, He also will deny us. 13 If we are faithless, He remains faithful; He cannot deny Himself.
2 Tim 4:1 I charge you therefore before God and the Lord Jesus Christ, who will judge the living and the dead at His appearing and His kingdom: 2 Preach the word! Be ready in season and out of season. Convince, rebuke, exhort, with all longsuffering and teaching. 3 For the time will come when they will not endure sound doctrine, but according to their own desires, because they have itching ears, they will heap up for themselves teachers; 4 and they will turn their ears away from the truth, and be turned aside to fables. 5 But you be watchful in all things, endure afflictions, do the work of an evangelist, fulfill your ministry.
James 5:10 My brethren, take the prophets, who spoke in the name of the Lord, as an example of suffering and patience. 11 Indeed we count them blessed who endure. You have heard of the perseverance of Job and seen the end intended by the Lord—that the Lord is very compassionate and merciful
Satan tempts us all the time with idols of the heart, but as these scriptures show we must endure to the end.
God bless
David.