Why do spirit-filled Christians interpret Scripture differently?

Scripture is clear that one of the ministries of the Holy Spirit is to illumine the minds of Christians so they can understand Scripture (1 Corinthians 2:13-14). This being the case, why do spirit-filled Christians sometimes have different understandings as to what certain Bible verses mean?

In answering this question, one might liken the Holy Spirit to a radio station that is transmitting a perfect signal. Even though that radio signal is transmitted perfectly, there are all kinds of different quality radio receivers out there. Some have good reception; some have poor reception. Some have a good antennae; others have a broken antennae. Some have good batteries; others are low on energy. The point is, different radio receivers have varying degrees of success in receiving that perfect signal.

Christians are much the same way. The Holy Spirit's "signal" (that is, His illumination) is always perfect. But because of varying circumstances (perhaps sin, or not fully walking in the Spirit, or being overly concerned about the affairs of the world, or being blinded by Satan), Christians have varying degrees of success in properly receiving the Spirit's illumination.