What Do I Know! A Summertime One-Pager with reference to Matthew 16:23 and Romans 12:113

In four verses we’ve moved from last Sunday’s Jesus saying to Peter:

Matthew 16:17–18 (NIV) …“Blessed are you, Simon son of Jonah, …I tell you that you are Peter, and on this rock I will build my church.

to

Matthew 16:23 Jesus turned and said to Peter, “Get behind me, Satan! You are a stumbling block to me; you do not have in mind the concerns of God, but merely human concerns.” 

Blessed are you to get behind me, Satan! Church foundation stone to stumbling block.
I am capable of just as quick a switch. I can go from the concerns of God (for example, concerned with suffering)to mine! and what I think would be better, in a moment, the twinkling of an appetite or an addiction. So can you.
How can I reduce that tendency?
A few days ago our daughter in law, Kristy Packwood posted on FaceBook that
Levi, our four year old grandson, was explaining to her the different jobs bugs have in their garden. When Kristy asked him how he knew all this his response was: "I'm a knower Mom. I just know things."
The first thing I can do to reduce my tendency to be a stumbling block holding Jesus back from what he wants to do in me and through me is to remember what I know and live as if I know what I know. For example, I know that from cover to cover the Bible tells me Jesus really is who Peter said he is. I know that as a baptized Christian the Holy Spirit is in me leading me there. I know it in my knower even when I have my doubts about whether I’m living up to who I am. In that sense I’m a knower like four year old Levi. So are many of you.
Second, if I do not want to be a speed bump on the narrow road that leads to life Jesus talked about (Mt 7:14) I need to know and act on what he says about how to live. For example, in this morning’s gospel—Mt 16:24, three things:

1. I must deny myself
2. take up the cross Jesus has for me, and 
3. follow Him. 

I don’t particularly like the part about denying myself and a cross. But I know that Jesus said it therefore I must pay attention and obey in practical ways such as how I use my time, the tasks I take on, how I use the money God has given me. Jesus is also saying quite clearly that if I focus on my own concerns and appetites instead of the things of God, I will lose my life. I might gain the whole world and its goodies but my soul would be forfeit. Same for you.
Here’s the third thing from this morning’s readings I know about how not be a stumbling blockhead. Paul in the Epistle: Romans 12:11 (NIV) Never be lacking (do not lag NRSV, do not be slothful ESV) in zeal, but keep your spiritual fervor (be ardent NRSV—fervent ESV in the spirit), serving the Lord.
Here’s my challenge as the wonderful, lazy days of summer turn into the brisker more demanding days of fall. I must not let delightful summertime restfulness turn into sloth and a lack of zeal for serving Jesus and His people. None of us should. I need to pray for God’s grace to empower me for that. So do you.
Ministry Fair Sunday is September 11th. Are there ways in which your zeal and fervor for serving the LORD can be rekindled, released and put into action here at St Barnabas? Even more importantly, is the Lord calling you to direct such zeal beyond these walls in some way?