1) Know your HOLY GOD intimately. When you have seen His glory, His holiness and His love by drawing close to Him in prayer then you can usually see through any counterfeits because you know the "real thing" so well.
2) Know your Bible. It is very important to be able to spot teachings that are either extra-biblical or directly opposed to what the Scriptures teach. However, it is important to remember that the Scribes and Pharisees were extremely learned in the Scriptures and yet they missed the very Messiah that was prophesied! So knowing the Bible is important – especially for doctrinal issues – but we need to be able to “discern the spirits” also.
2) Know your Bible. It is very important to be able to spot teachings that are either extra-biblical or directly opposed to what the Scriptures teach. However, it is important to remember that the Scribes and Pharisees were extremely learned in the Scriptures and yet they missed the very Messiah that was prophesied! So knowing the Bible is important – especially for doctrinal issues – but we need to be able to “discern the spirits” also.
3) Be a “lover of truth”. This is very crucial. Are you someone who will actually stand up for Truth – even against the crowd? Or do you remain silent even when you are convinced something is very wrong?
4) Purity of heart and Humility. Many deceptions only appeal to us because there is something inside us that “wants” to believe them. They are seductive because of darkness and wrong motives in our own lives. We must search our hearts and root these out.
5) The ‘inner witness’ of the Holy Spirit. We must learn to never over-ride this “still small voice”, as it will save us from deception again and again.
[Andrew Strom - RevivalSchool.Com]