Today is the 10th day of our journey to the sayings of the Ascetics of the Orthodox Church.
The section we are going to study is about :
Unbelief
Falsehood - and only falsehood - separates us from God ... False thoughts, false words, false feelings, false desires - Behold the aggregate of lies that leads us to non-being, illusion, and rejection of God.
(St. Nicholas of Serbia, Thoughts on Good and Evil)
The Lord does not show Himself to a proud soul. The proud soul, no matter how many books it reads, will never know God, since by its pride it does not give place for the grace of the Holy Spirit, while God is known only by the humble soul.
(St. Silouan the Athonite, Writings, III.11)
Each of us can discuss God inasmuch as he has known the grace of the Holy Spirit; for how can we think of or discuss what we haven't seen, or haven't head of, or don't know? The saints say that they have seen God, but there are people who say that there is no God. Clearly, they say this because they haven't known God, but this does not at all mean that He is not. The saints speak of that which they have truly seen and know.
(St. Silouan the Athonite, Writings, VIII.9)
Pride does not allow the soul to set out on the path of faith. Here is my advice to the unbeliever: let him say, "Lord, if you exist, then illumine me, and I will serve you with all my heart and soul." And for this humble thought and readiness to serve God, the Lord will immediately illumine him... And then your soul will sense the Lord; she will sense that the Lord has forgiven her, and loves her, and you will know this from experience, and the grace of the Holy Spirit will be a witness in your soul of your salvation, and you will want to cry out to the whole world: "The Lord loves us so much!"
(St. Silouan the Athonite, Writings, III.6)
Only one who guards himself from all sin can have sincere and fervent faith. Faith is only preserved in the presence of good morals.
(St. Nikon of Optina)
http://orthodox.cn/patristics/300sayings_en.htm